1892 correspondence between
Octave Chanute and Louis Pierre Mouillard

4 January 1892

Octave Chanute to Louis-Pierre Mouillard

A few days ago I received your kind letter of 27 November and I am glad to learn that your health is improving.

I returned from New York where I spent some time in the interest of the Society of Civil Engineers. I saw my friend who owns a yacht, but owing to lack of time he could only make rather unimportant experiments with the "lubricator." However, he noticed that the thin streams of crude oil have a tendency to rise directly to the surface instead of being distributed along the hull. Consequently the effect is trifling. He thinks that the distribution pipes should be placed all along the ship and that it would be better to make an emulsion of the water and the oil in order to separate the globules before discharging them against the hull. As soon as spring is here, he is ready to try this latter method. He does not believe that air would be efficient, as it is much lighter than water and therefore would rise to the surface at once instead of passing to the rear (of the ship). One could also put a pipe under the keel, all along the ship, to distribute the air or the oil. But how could this be arranged on ships which are already launched and how, in case of need, could such an arrangement be inspected or repaired?

However, I believe that all this can be solved. It is necessary to work out the results of experiments, which almost always interfere between an original idea and its realization. In order to expedite matters I intend to let another friend of mine in on your idea so he, or his part, may also make experiments. As this increases somewhat the chances of appropriation by somebody else, I am thinking of placing a "caveat" in your name with the patent office. This is a kind of date fixing which prevents other inventors from patenting a similar invention within one year, if one is not quite ready to take out a patent oneself. The only thing I am afraid of is that you may think that I am not working fast enough. For a start I selected the "lubricator" as it is the simplest of your ideas. However, I am ready any time to switch to something else, if you so desire.

17 January 1892

Octave Chanute to Louis-Pierre Mouillard

I received your kind letter of 10 December, also of the 15th concerning the high speed railway.

I am leaving this evening for Washington to come to terms with Mr. Whittlesey (patent lawyer) in regard to your "lubricator," and also to hand your book over to Mr. Langley personally.

At the same time, I plan to see some officers of the U. S. Navy in reference to your ship design and also the engineers who are about to make experiments with a high speed train model near Washington. This is the model I told you about some time ago. However, I must tell you that after having read your letter of the 15th and reread the chapter on "penetration" I am wondering whether your conveyor would not have more speed if the butt-end was in front. This is indicated by the form of the bluntest part of birds and fishes, and those which you recommend as models deal with ice almost as much as with water. Moreover, the theory that the streamlines when they come together again cannot create a propelling force when the stern is longer than the stem, seemed always correct to me. I therefore am taking the liberty to make some reservations when showing your designs, and leave it up to the experiment (if I can have one made) to decide whether the machine should travel with the blunt end in front or in the rear.

In one of your letters you asked me to get you some information in reference to experiments with look-out balloons. I am sending you everything I could get, also other newspaper clippings which might be of interest to you, including an article by Mr. Maxim.

Unfortunately most of this matter is in English, but I hope you may be able to manage it.

I have about half of your book translated and I shall mail it to you as soon as Mr. Langley has read it. I have to work somewhat by fits and starts because I have to attend to so many things.

I started with the designs for an airplane as a first attempt, according to your method. But the breaking strength of the materials is a terrible stumbling block. You would greatly oblige me if you would give me fuller instructions if you want me to make experiments.

27 January 1892

Octave Chanute to Louis-Pierre Mouillard

I returned from Washington where I handed over your book and most of your letters to Mr. Langley personally.

Before accepting the book he asked me whether it contained some ideas on aviation which are patentable. When I answered him in the affirmative, he asked me to keep the chapters in which these ideas appear, because, said he, one never knows how an idea creeps into one's mind. He does not want to unwittingly expose himself to appropriating something that belongs to you.

I first insisted that he take the complete book but then according to his wishes I retained the chapters "Trial Airplane", "Horizontal Control" and "Vertical Control Surface", also several letters which give some details on these subjects.

Your book will be kept in a safe, and I put each chapter in a separate envelope so that the pages, which I first numbered with a pencil, do not get lost.

My first idea was to build a trial airplane before applying for a patent for you, because one never knows exactly, as long as the idea has not been put into practice at all, what and how many points the patent should cover. But due to an incident in reference to the "lubricator" which I shall explain later, I began to change my mind.

Therefore, I believe that it would be much better to apply for a patent for the glider in your name at once and to supplement this patent later on by others if necessary.

In case this procedure meets with your approval I kindly ask you to send me everything necessary to have the papers prepared for your signature. Also advise in what countries you deem it of advantage to patent your glider, so that I can take the matter up with Mr. Whittlesey on the proceedings, to apply for patents simultaneously in the various countries.

To tell you the truth, I, for my part, would prefer that you apply for a patent for your invention in France first, and that you send me your drawings and documents when your interests are covered by the proceedings in France. It is true that you would lose two years on the American patent which is 17 years instead of 15, but which expires at the same time as the foreign patent if the latter antedates the American patent. However you would be sure in this case that the patent is valid as you intend it to be, furthermore that I have not appropriated anything from you if I should decide later on to apply for a patent myself for the ideas as I told you about and for others which may arise.

In case you decide to start with the French patent, let me know how much money to send you to defray its costs and those of the copies you are going to send me. Under separate cover I am mailing you some information in English pertaining to American laws relating to patents.

As to the incident concerning the "lubricator", I chanced to read in the London technical magazine Engineering of January 1 a letter of General Hutchinson who proposes approximately the same idea as you. I have translated this letter in its entirety and herewith enclose it. Moreover several months ago Mr. Langley was struck by the same idea, while studying the porpoise which is a sea fish which exudes oil over its entire surface, but Mr. Langley does not intend to take out a patent.

After a consultation with Mr. Whittlesey, I believe, that instead of applying for a "caveat" for you, it would be much better to apply at once for a patent which should contain all the variations you can think of, so nobody can apply the idea whatsoever merely in a somewhat different way to dodge the patent. The papers are being prepared and I expect to get them within a week when I shall mail them to you to sign them as soon as they get there.

Fortunately it may be seen that General Hutchinson's idea is still rather imperfect.

It is also fortunate that I correspond with him and have rendered him a small service by advising him of a method relative to his invention to keep a balloon always inflated. Therefore, I wrote him that I am experimenting with the same idea (lubricator) and asked him whether he intends to apply for a patent. The only thing that worries me is: what is absolutely the best way to avoid any waste of crude oil in order to produce results with the least quantity possible.

Translation of an article published in "Engineering" of London, January 1, 1892, p. 20


To the Editor of Engineering

Sir, - The security obtained by ships in stormy weather from a thin film of oil smoothing the surface of an agitated sea has often been described in the public papers, but no remark seems ever to have been made respecting the increase to speed that would be gained were such a film spread over the submerged surface of a vessel. The increase would be so great that surely some thought should be given to the subject before it is dismissed as chimerical and impracticable.

The cohesion that has been manifested by the particles in the thin layer is so encouraging that it seems well worth while to consider whether numerous minute streams of oil could not be ejected in direct contact with the submerged surface through holes in the aftermost side of flanged vertical pipes, much flattened to prevent opposition to progress. On the principle by which at a fire water is drawn up and expelled with power from the engine, oil, taken from supply casks, would be forced against the ship's sides with but little exercise of steam or mechanical power. As the ship progresses, the oil, meeting the water, would be pressed towards the stern, while the inward pressure of the water would prevent the oil from quitting the ship's side. Horizontal, slightly indented lines would aid the flow of the oil towards the stern. It is possible that some day ships may be built with depressed grooves for receiving the oil, in order to dispense with pipes, which more or less break the even surface of the ship's sides.

At the bow a centrically fixed vertical pipe would discharge oil from both sides.

The lateral pressure of the water and the cohesiveness of the particles of oil would resist its rising to the surface while the ship was under sail or steam. In harbors which have tides on a ship's swinging her anchor, the oil would spread over the bottom as effectually as if she were at sea. In tideless harbors the oil would be expelled from a pipe or pipes attached lengthwise to the keel.

An oil would be selected of the quality and consistency best calculated to meet the desired purpose, and it would be so treated chemically as to prove inimical to the growth of weeds and barnacles.

Chemistry is constantly making such marvelous strides in useful discoveries that it may be possible before long to obtain a mixture for which oil would have a greater affinity then water. Such a mixture rubbed over a ship's bottom before she left her drydock would render success certain.

Surely by ingenuity and an exercise of the inventive talent possessed by many of our engineers, experiments could be made at a trifling cost that would show whether there was a reasonable prospect of their labor being superabundantly rewarded were energetic steps adopted - a success that by diminishing the length of voyages would diminish expenses and risk at sea in peace as well as war, thereby greatly aiding commerce.

Would not some light be thrown on this important subject were a duly bent, vertical board, running upon wheels, to travel round and round in an annular trough filled with water? Attached to the exterior side of the board would be several vertical, perforated pipes, as described, fed with oil (from a cask at a considerable height) flowing through a vertical central tube, terminating in horizontal radial tubes, one to each pipe. The radial arrangement would be united to the stationary central tube by a socket joint open in its center. By an arrangement acting below the joint on a central fixture, the board could be driven in a circle at any required rate, but never so rapidly that the spreading of the oil could be affected by centrifugal force.

Could the proposed coat of oil be given to the submerged surface of any ship, it would be difficult to determine what might not be her gain in speed, for the repugnance, as we may call it, of oil to adherence with water shows that practically there would be no skin friction.

Your obedient servant, W. N. Hutchinson, General. December 28, 1891

31 January 1892

Octave Chanute to Louis-Pierre Mouillard

Enclosed you will find:

  1. Application, description and oath required by American law to take out an American patent for the "lubricator".
  2. Blueprint of the drawing attached thereto. (A drawing has been stupidly copied on the wrong side, but it is not worthwhile to lose time waiting for another copy.) Point out to me all variations which you have thought of and we will put them in.
  3. Mr. Whittlesey's letter in English.
  4. A translation of this letter. I made a cross-mark on the empty spaces to be filled in as explained in this letter.

As you will have to complete the papers before an official of the United States who necessarily speaks English and so can explain them to you, I did not translate them, besides I am very busy. However, I kindly ask you to have him explain well to you the description (specification) made of your invention and to mail me any improvements and amplifications you have in mind. We may take out or add typewritten pages between the official printed ones. It is my desire that your patent should be as complete and of as wide a scope as possible.

3 February 1892

Louis-Pierre Mouillard to Octave Chanute

I herewith confirm my letter in regard to high-speed railroads. This is in reply to your kind letter of January 4.

The experiments which your friend made on his yacht are quite contrary to what has been devised and to what is going to take place in practice.

He says "that the oil streams have a tendency to rise directly to the surface instead of being distributed over the hull and that consequently the effect was negligible."

First of all, it is only possible to produce continuous oil streams when the ship is at absolute rest. As soon as the ship makes any forward motion the oil stream is intersected. The sections will be the shorter and more numerous, the higher the speed, so that, when the speed reaches 20 knots, each section chopped off the oil stream will be certainly not even as big as the head of a pin. The rising of these droplets to the surface is not as easy to apprehend as it may seem at first sight. The speed with which they come to the surface depends 1.) on the density of the oil, 2.) on the size of the droplets, 3.) on the depth from where they are ejected. If the density of the oil is good, the point where the droplet arrives on the surface will be the farther from the perpendicular, the faster the ship travels. This is an indisputable fact. It even may be possible that the oil greases the screw and the rudder or even goes to waste without having touched the ship at all. This will happen if the droplets are too small while the speed of the ship is very high. Such a case should be avoided as it means a dead loss of material. To remedy matters it is only necessary to increase the size of the droplets.

However, there are certain difficulties in connection with the production of properly sized droplets. The density of the oil is hard to change. Addition of mineral salts to increase its density is not practical and besides, expensive, so this method is out of consideration. The wisest thing to do is to select the most adaptable oil. I have already mentioned crude oil just as it comes from the well. It needs no other preparation but filtering which takes out the dirt. As there is no means of changing the density other measures must be considered. The first idea would seem to discharge the oil in the lubricator at a speed which would cut the oil stream into properly sized drops. However, this method is not applicable, because it requires an unchanged speed of the ship; once under way it must proceed at a uniform speed. Considering the size of the holes from which the oil is ejected into the sea, this size is invariable, at least for the duration of the trip. To increase or decrease these holes is a delicate operation which could only be done in dry dock. So this method is out of consideration.

There remains only one way: a regulating device of the force needed to eject the oil. Such a regulator will be always under control; one has always the choice between ejecting one liter or several liters at any one time, or if a pressure injector is used between, ejecting plenty of oil under strong pressure or a little at a time, and let it flow out almost by itself. These are the guiding principles and it will be up to the man in charge to estimate the course to use by an attentive study of the log and of the wake the ship. The wake will be more or less brilliant due to droplets that did not attach themselves to the hull.

As a good rule I estimate that the oil should almost be completely deposited on the front half of the ship. The rear half will be greased by the forward motion of the ship, the oil will be dragged along and pushed to the extreme rear by the friction of the water on the ship.

So you see that the lubrication, notwithstanding its great simplicity, requires much consideration in order to be employed efficiently.

The advantages and disadvantages of this lubricator will be discussed by those interested in sea transportation, as soon as they learn about it when the patent is taken out. You probably will be questioned about it very often.

The best explanation can be given by experimentation which will determine the value of this method.

For a simple experimentation it is necessary to adapt the lubricator to ships in actual service. This could be done in the following manner: T is the extreme point of the fore part of the ship's prow. L is the lubricator consisting of a triangular copper pipe which is perforated at a and a' to release the oil on both sides of the ship. This triangular pipe is well riveted to the prow at R, R1, R2 and R3 and cannot be torn away by the waves because it forms a solid unit with the ship's structure; besides, it is constantly supported by the forward motion of the ship. The construction and installation of this device are so simple that it is unnecessary to waste any more words about it.


As to the length of the pipe, it should be as long as the entire prow and should pass below the structure and cover at least one third of the depth of the keel. In any case one half of the length of the keel would be amply sufficient because owing to the pitching of the ship the waves will pass the extreme rear at the point where the oil is ejected and is about to rise to the surface. This certainly should be sufficient to grease the rear of the hull and even the rudder.

This experimental arrangement is necessarily extremely fragile. While in port, the first chain which comes in contact with the fore part of the ship, or the first small craft which turns around it and bumps against it are apt to damage the lubricator. It therefore should be protected without fear of any damage. While this trial arrangement may not be perfect, it makes possible to experiment at very small expense.

Now, dear sir, permit me to ask you for some information. I am very anxious to know what you have decided to do about my book and what you intend to do with my ship and its accessories. Furthermore you would greatly oblige me by telling me how you think to present my lubricator in the newspapers and before the public, the same lubricator with which you wanted to get things going. I admit, I have not formed an opinion about it. I presume that a start has been made and I have the greatest faith that it will work well; only it seems to me that it should be presented in such a way that it may be discussed and tried out, but not to risk it to be appropriated and so to interfere with taking out a patent. It seems to me that once you have the patent you will be in an exceptional position to offer it for sale.

If at the same time, you would be kind enough to inform me in a few words what you decide to do about the Alpine balloon and the airplane you would greatly oblige me. I kindly ask you to excuse my curiosity and to blame it on the distance which separates us.

11 February 1892

Octave Chanute to Louis-Pierre Mouillard

On January 17, I wrote you in reference to your book, on the 27th in regard to your lubricator, and on the 31st I mailed you the patent for your signature. I hope you received everything.

I asked Mr. Whittlesey to send you all American patents which resemble your glider, according to the enclosed list. You must have seen Du Temple's, d'Esterno's, and Ader's patents which come close to yours. In order to take out a valid patent it will be necessary to single out what is new and useful on your machine in comparison with what has already been patented by others. If you should decide to take out a patent in France first, I believe Mr. Dieuaide, 62 Rue de Provence, knows this line of business better than anybody else.

I am going to leave on a trip to the South and then to California. I may be away for two months, but my mail will be forwarded to me so that there will not be much delay. I have three chapters of your book and Mr. Langley has the rest. Should anything happen to me, I have made such arrangements as to have all this material returned to you.

I think your book should be published as soon as your inventions are covered by patents.

They are, as I recall:

  1. Airplane
  2. Dirigible parachute
  3. Balloon valve
  4. Alpine balloon

To tell the truth, I do not believe there is much money to be made with the dirigible parachute nor with the Alpine balloon, and I am not able to pass judgment on your balloon valve. I have read carefully the chapter on kites and found nothing in it to be patented. The chapter is too short and would be more interesting if you would discuss kites in twice the words.

The shape of the ship lubricator, the rotation indicator, the rational propeller, the observation post for the Navy, the dirigible balloon without engine, the Navy torpedoes, the ore separator, and the dew collector are not mentioned in the book, so you are the sole owner of them.

In my opinion your principal invention is the airplane and I would even suggest that you disregard all the others so that you may be able to give your entire attention to the development of the glider. The conception of a basic idea as a unit is one thing, but its realization by combining all the elements capable of resulting in final success is quite another thing.

Cairo, 23 February 1892

Louis-Pierre Mouillard to Octave Chanute

I herewith return the application signed by the U.S. consul in Cairo. I hope everything is alright.

There is another matter which I hope you will do me the favor to accept namely to place this patent under your patronage. You told me that "good deeds make good friends," so please permit me, dear sir, to return this citation and to tell you. If the subject treated in this patent, if the idea therein expressed does not seem to you to be too insignificant you would give me a real great pleasure if you would make the ownership of this patent read: 0. Chanute and Mouillard.

As to the patent of the airplane which you suggest to be applied for in order to demonstrate gliding as explained in my books, I wish to tell you that I am too far removed from the civilized world. Actually the United States are far in the lead in this movement, while, alas, Cairo is so far away; for this kind of idea it is an absolute desert. You would greatly oblige me if you would take this matter into your own hands as I do not know how to proceed. And always, if you please, under the condition that any patent taken out in this way should be issued to O. Chanute and Mouillard.

Last December I mailed you a letter in regard to the shape to be given to a high speed train. Please advise whether you received it, and what you think of it.

With sorrow and regret I read Mr. Langley's decision not to accept those chapters of my book which contain patentable ideas. I do not know whether the value of what is expressed in these chapters is over estimated, but it seems to me, that he would have found certain interesting points. When the time comes that you have the patent, I hope that he will have no more objections to acquaint himself with the rest of my book. He then will have an explanation of the machine which I hope will interest him.

When you write Mr. Langley please convey to him my most sincere thanks for the interest he has shown toward me.

And you, dear sir, I really do not know how to appreciate your great kindness toward me.

Cairo, 25 February 1892

Louis-Pierre Mouillard to Octave Chanut

Perusing the description of the patent, I noticed some new addition that I believe should be credited to you, dear sir, it is a point where there is a matter of mixing water and oil. I had thought of this mixture but had hesitated to mention it. Since it is mentioned in this paper, allow me to elaborate on it.

Oil can be mixed with water only if it undergoes a chemical change that can be obtained by mixing it with soap. In this case an oil emulsion results that makes it soluble. This is one of many possible transformations of this liquid which I have mentioned several months ago, when I mentioned among other things to dissolve euphorbial resin which has the property to prevent rust on iron. Therefore, this point should also appear in the patent.

When the description was read to me I noticed a passage which mentions the air blower. This blower, or in other words blowing compressed air before or after the introduction of the quantity of oil, has the purpose to specify the point of the pipes where the oil is supposed to be ejected.

If the oil is to go to the bottom of the pipes, that is to the deepest point, air is blown into the pipes to drive the water out of them and thus to make them empty. After this procedure, oil is let into the tubes and flows to their deepest point, as there is no more water to obstruct this flow.

If, on the contrary, the surface (of those tubes) is to be greased, the water is not driven out of the pipes by compressed air. The column of oil acts by itself, as due to its height (less small difference of density) it pushes back the column of water. In this way the oil remains near the surface and is ejected at this point.

As to the blower, I have to admit that I have not formed a clear opinion on the good or bad action of the air bubble as a correct medium to decide on the gliding of the ship through the waves. A log accurate enough to indicate an increase or decrease by a fraction of a knot would be the only means to settle that question. However, there are two other useful actions of the air bubble which I think should be explained.

The first would be that it presses the oil droplet against the side of the ship and fixes it there by means of plain mechanical compression, because its ascending force is very great. (The difference of the density of air and water is 1.3 : 1000). So the air bubble is in this case a mechanical medium, a compressor.

The second action should have been made clear to you when I answered your questions on the effect of billows on the large flat surface of my ship. I admit I did what one often does, I answered beside the question. When a large mass of air is blown by powerful ventilators to the extreme front which has been transformed into an immense prismatic pipe with thousands of holes, the effect looked for of the large blower is to use the air bubble as an elastic cushion to absorb the violence of the shocks of the waves in order to reduce the breaking action of the billows. As a matter of fact, on ships without a blower, the shock of the water (an incompressible fluid) on the steel plates forces these plates to bend constantly because the bearing action of the ship is slow, the water does not give way at once and the ship does not give way either by rising which takes place only a few instants later, so the plates form an elastic cushion and withstand the shock.

However, when there is a large quantity of big air bubbles, a gas which is extremely elastic, between the sides of the ship and the waves, the pressure of the shock acts first on these air bubbles and decreases their volume, in this way the plates will be a great deal relieved; between them and the turbulent water will be a cushion of an absolute elasticity which protects the plates from the dangerous shocks which stagger the ship, loosen the rivets, and most of all stop the motion of the ship.

In my last letter I showed you how I thought this device should be constructed. By necessity this is a simple and imperfect way because it is to be adapted on ships in actual service. Here is the way the device should in my opinion be installed on large liners to be built.

The drawing (fig.71) represents the nose of the ship. A is an inlet tube for compressed air under a pressure of about 1.5 atm. If cock 1 is opened, the air is forced into the lubricator L, L1, L2. If cock 1 is closed and cock 2 is opened, compressed air is forced into the oil tank keeping the oil under pressure. Cock 3 controls a tube which draws oil from the tank and feeds it into the lubricator. D and Dl are pressure gauges. In order to let the oil flow out on the surface, cock 2 is opened. The oil is put under a pressure which is recorded by gauge D1, then cock 3 is opened and the oil is forced into a pipe which is the lubricator.

Fig. 71

If the oil shall be sent to the lowest part of the lubricator under the ship, at L1, L2 for example, cock 1 is opened causing the air to push out the water column which flows out through the holes and through the lower end of L2 which is open. When the lubricator is empty, cock 1 is closed and cock 2 is opened, then after a few moments, cock 3 is opened also. Here is what takes place. If the three cocks were opened at the same time the pressure would be uniform, but if cock 1 is closed, the pressure of 1.5 atm is expected to drop. It decreases because a part of the air escapes through the holes of the lubricator, therefore the pressure becomes less than 1.5 atm. The oil itself is under a pressure of exactly 1.5 atmospheres. The oil will flow with a force in proportion to the time that elapsed between the two operations. The difference between the two pressures may be easily verified by watching the gages. D1 will indicate 1.5 atm while D indicates the decreasing pressures. Mouillard

Note: The oil tank should have many perforated partitions to counteract the motion of the oil.

Note: The inflammable liquid which is considered hazardous is completely isolated in the fore part in an entirely enclosed place. A single man controls the operation by opening and closing three cocks. When the device is properly taken care of, spilling of oil should be almost nil. Therefore, there is no cause to argue about fire hazard.

Cairo, 7 March 1892

Louis-Pierre Mouillard to Octave Chanute

On February 26, I returned to you by registered mail the patent, stamped and signed by the US Consul General in Cairo.

On March 3, I received from Mr. Whittlesey five copies of patents granted in the USA on the problem of aviation. I shall study them as soon as I see my translator and shall report to you on them in my next letter. This letter will also take up the subject of the airplane to be patented, according to the wish expressed in your letter of February 11, which I just received.

This letter contains a study of variable pitch propellers.

You may have noticed in L'Aeronaute of July 1891, pages 165 and 166, also in its issue of January 1892, page 18, that this type of propellers creates great interest. It remains to be seen whether they are in actual use and whether they have been patented. In any case, as I do not copy from anybody, it is probable that mine may differ in many points from those which are proposed, some indications to that effect can be found on pages 165-6 of L'Aeronaute. The ideas are based on the same consideration. But as I do not know them, as I do not care what somebody else is doing, I do not appropriate anything of anybody. As the objectives to be attained are different it is very probable that the propellers must differ from one another.

Mr. Hureau de Villeneuve should have this information, because he knew Crocé-Spinelli, and others who devoted themselves to this type of propellers.

These propellers are certainly not identical and I suppose that the two pressure regulators ­ one for rivers and one for the sea ­ are entirely new, as well as the log that makes it possible to balance their action, they have nothing to do with this case. Therefore the question is to compare the production and to patent new ideas if there are any.

I think I should have brought them out twenty years ago, but could not. Notwithstanding this delay, I think you will judge it advisable to study the problem, because the propeller is such a big proposition. At any rate there should be a possibility of taking out a patent for variations or improvements, the law cannot stop the complete study of such an important question by means of a patent. This is for the experts to decide.

This letter may arrive a few days before your return from your extensive tour to the South and California. I hope that this trip has been a happy one for you and that it has not tired you out too much.

From the standpoint of observing birds, you may have encountered, it is too bad that your voyage took place in February and March. This is a poor time for studying the large soaring birds because they are busy with their nests and do not congregate. You therefore, may have seen solitary birds only.

I hope you have seen in the South the small aura and urubu vultures that may be found around towns. These are birds with grey and black plumage, but their flight has nothing remarkable to offer. Then perhaps a bird with brilliant yellow and violet colors and a gaudily red head and caruncle like a big turkey, its soaring flight should be of some interest (Sarcorhamphus papa). But above all, when crossing the Rocky Mountains you may come across the large vultures, the condor and the catharista. These two birds are able to execute soaring flight in a most conclusive manner. Their flight is a spectacle to be wished for by everyone who likes aviation, and is a demonstrative lesson which supports my theory.

I hope you had good eyesight so you could observe with attention the scenery and the flight of the birds, so that you may tell me all the motions they went through.

As I know theoretically the birds of North America as well as those of the Old World, I might perhaps be able to tell you what kind you have seen.

I wish to thank you very much for what you had to say about my book in the February 1892 issue of the Railroad and Engineering Journal; I also thank you for the other numbers you were kind enough to send me; they are of great interest to me.

19 April 1892

Letter from Louis-Pierre Mouillard to Octave Chanute - Missing

20 May 1892

Octave Chanute to Louis-Pierre Mouillard

On my return from California I received your letter of April 19, with the drawings of your airplane.

Up to now I am busy preparing the drawings and the description in English so that Mr. Whittlesey can make application for the patent. I may have to ask you some questions, so as to make absolutely certain that all your ideas are covered.

For instance: Do you expect that this machine will create suction and move against the wind with flat surfaces on the bottom side, without losing altitude? I doubt it. In your report you state: "Then the wing tips are turned forward, the load moves toward the rear and the airplane rises." I understand that but does it move forward at the same time? Does it not rather drift, a motion which birds are forced to make only at high wind. Please give me more particulars about the motions which you believe are possible with this airplane.

When you have a chance, study D'Esterno's patent. In his balance English patent he cites three principles to be observed; equilibrium, control and impulse. He gets the first by changing the position of the center of gravity, the second by changing the position of the wings and of the center of gravity, and third by flapping the wings, He says wind is necessary for gliding flight.

Examine also Du Temple's patent. He says that the equilibrium is produced by the motion of the wings in relation to the center of gravity. Control of vertical direction is obtained by means of the tail and horizontal control by the motion of wings and tail.

It is very probable that these two patents are being held against us and I want to be prepared to defend our interests.

I thought I could tell you in this letter about what I saw in California. However, I have to postpone it, as I had to attend to various other matters on my return. But I believe that this will be the topic of my next letter which will be a rather long one.

Kindly let me know how much deposit money would be necessary to publish your book in France. In America I found a publisher who wants to print an English edition at his own expense and to pay you 10 percent of the gross receipts. With a handshake I am, O. Chanute . Note the change of address: 413 Huron St.

Cairo, 14 June 1892

Louis-Pierre Mouillard to Octave Chanute

I hasten to answer your questions submitted to me in your kind letter of May 20.

Question: "Do you think this machine is able to create suction?"

Answer is certainly yes! and a thousand times yes! and lift also, or two and two do not equal four! The master does it and its pupil, man, will do it, and by the identical means. One may object that the master is the bird which is created with an inherent knowledge of flight, with muscles of incomparable power, and with a perfect structure to carry out this locomotion. My reply is: Among the various maneuvers the bird is able to perform, humanity is interested in one: Flying from place to place. As this kind of flight is made in a number of manners by the various families of birds, we make a selection among them and take as a model the one whose maneuvers may be imitated. This is the family of the large vultures. Continuing our selection in regard to the flight of this family we eliminate any action which is not quite absolutely an action of translation, and we arrive at "flight without flapping wings" which is expounded in my two books on aviation. The disadvantage of the human airplane will be the difficulty to make it large and strong. However, it will have as advantages the slowness during maneuvers and a gliding capacity without equal due to the greater importance of its mass. Therefore one may admit that there is equality.

More and more I get a clear idea of the road I have laid out but also of the difficulty to transmit it to the human intelligence. What may be the reason that I alone should understand? I believe it is due to two causes: First, that I have been placed into a better position to observe than most of the investigators; then, perhaps, due to a particular individual characteristic, namely a great love for the sport of gliding. There are people who love horses, others who like boats, and others again who like bicycles; but I confess of having always been impressed by gliding. My first teachers were a plain family of kestrels. All their activities whereby they employed flapping wings left me absolutely indifferent. But when they started to glide, my attention was aroused, causing me at once to think of a medium to reproduce this maneuver which only requires intelligence, dexterity, and - so to speak - no waste of power. Later the stork, due to the greater extent of its motions, helped to disentangle a large number of points which the small size of the kestrels prevented me from analyzing; then finally I met the master, the large vulture, a bird in whose flight there is very little to eliminate. This bird, not I, is the real author of my two books. I am only a plain copyist, a poor photographer. This bird is much more explicit and more affirmative than I have ever been, despite my style as a prophet. This bird alone demonstrates, all I can do is to say: I have seen.

To top it all, it is unfortunate that it is so hard to make others see these convincing flight motions of which I am speaking. Bregewischt and Basin have seen nothing, so to speak, while Biot refers to my descriptions. At last, you dear sir, reading between the lines of your letters, it seems to me that your report of your trip is filled with an emphasized doubt. I understand that all you ask yourself, at times, whether L.P. Mouillard is a fanatic, whether he observes well, and whether he analyzes soundly what he has seen.

The trouble with my work is that it affects any idea which is not expressed at the proper time. My two books are twenty years ahead of their time and that is their original sin.

The evolution of flight without flapping wings will be admitted only under one condition, i.e., when others, whose attention will have been aroused by my preachings, will see for themselves and then tell the aviators. This flight motion as it has been described is a reality; he has observed well and here is the proper road to follow.

Or else, a precise demonstration with experiments by means of an airplane.

Without being too commonplace we may very well consider the fact that twenty years is too long to wait and that it would be much better for us to hasten the movement a bit to increase its progression. I, for my part, believe that it takes less time to show by practical demonstration than to wait until the world has understood. If possible, let us therefore, experiment, let us try to demonstrate repeatedly, at first simple gliding flight (not once as I have done or as Ader's machine has done). As the airplane which I propose has some other qualities, these simple glides may be followed by more complicated maneuvers, ascending or climbing flight, which makes everything possible.

Now let us get back to this airplane and to the maneuvers it will be able to execute. This machine is going to live up to its properties or will fly efficiently, i.e., execute unlimited flight only when there is enough wind so that it may draw the power necessary to arise from the force of the air current. The velocity of this air current indispensable for indefinite lift and for takeoff varies according to the weight of the machine, the weight of the pilot, the size of the lifting surface, the degree of perfection of the shape and the gliding quality of this surface, also finally according to the maneuvers to be executed.

It would be well to consider the surface necessary for the various flight motions. If the flight is to be slow the surface must be larger than for fast flight.

As the experiments require slowness it will be obtained by means of a surface which is loaded by less than 5 kilograms per square meter and which is constructed in a proportion 5 to 1, with the span of the wing to be 5 and its width 1. Under these conditions, a wind velocity of 5 meters per second will be the lowest limit; below that no flight will be possible. More velocity creates a higher lifting power which when it reaches a certain limit will improve the flight of the airplane, this limit is about 20 meters per second.

Let us take an average wind of 12.50 meters and let us repeat the maneuvers which may be executed with such an airplane.

Soaring and lifting may be produced by the speed impelled. By 1.) a drop from a height of 25 meters. 2.) To give the machine by any launching method whatever a speed which together with the head wind will result in a total velocity of 15 meters per second. 3.) By means of the displacement of the center of gravity of the load under the action of a wind of less than 15 meters per second. This maneuver is carried out as follows: The nose of the airplane points into the wind and the wings are placed as far to the rear as possible. Then if the wing tips are moved forward, this simple motion causes the machine to rise and to move forward.

As soon as this machine moves in turbulent air at a speed which is able to carry it, it may produce: suction, which means motion against the wind without falling or rising, aspiration while rising, crosswise motion to the right or to the left, flight with rear wind, and finally climbing by means of circular flight.

Therefore, it will be possible to reproduce with this machine all motions necessary for a cross country flight, provided that all conditions enumerated above are combined: wind 12.50 meters, load 5000 grams per square meter, and a ratio of at least 5:1.

Here is my opinion of the patents to which you called my attention: patent d'Esterno. All I know of him is what you told me, but this simple explanation shows that his machine is entirely different than ours.

He gets "equilibrium by varying the position of the center of gravity." So do we, only the methods used to accomplish are quite different. Control "by changing the position of the wings and of the center of gravity."

This I do not understand and on the reproduction of Dielaide's (sp?) picture I do not see how he proceeds to do so. It is one thing to control and another to be controlled.

Motive power by means of flapping the wings. So it is a flapping wing plane. This difference alone settles the question in a very positive way. The airplane which he patented is a flapping wing plane, while ours is the quintessence of gliding, the airplane which flies without flapping wings, and the fact that we made the wings rigid is the proof of it.

Patent Du Temple: In the chapter "Aviation" I wrote that this airplane is remarkable by its extraordinary simple construction, too simple in fact because it is not strong enough. I also say that no other control but that which may be introduced by the tail is indicated. After all, perhaps it is otherwise in the patent, Dielaide's (sp?) drawings are so much lacking in details that one does not dare to express one's opinion. If there is really nothing but the tail for control, Du Temple can not defy our two control methods. But what settles the question is the propeller in front which shows that there is no relation whatever between a pulled airplane and our machine which is actuated by the wind and by deviation.

Now I come to the last paragraph of your kind letter. First of all I must thank you for your kindness and I do it wholeheartedly. You are rendering me a very great service. L'Empire de l'Air cost me about 2400 francs. The success it had in the newspapers was by no means due to G. Masson the publisher, but to a chum of mine, A. Daudet, who opened all the doors of publicity for me. G. Masson is expensive. You have to pay for his name as a publisher. I had to make all the corrections and yet the book is full of mistakes. Especially the drawings caused me great trouble, I had to do the frontispiece all over again on a one meter scale so the designer could grasp it, and what a horror it turned out to be in spite of it. Le Vol sans Battement is without illustrations, the two or three I had for it I omitted in order to save money and to have only plain printing.

I am told that in Paris the rate for printing is 60 francs for 16 pages which would mean about 1500 francs for 300 and some pages. There remains the question of proofreading. I cannot think of having the proof sheets sent back and forth, there would never be an end to it. Perhaps Mr. Hureau de Villeneuve will have the kindness to help me out. I shall ask him about it as well as about the price the other printers charge. I shall also write to G. Masson to get his price.

As to the English publisher for the translation of this book and even for L'Empire de l'Air when it comes out, it seems to me that I should accept with both hands if you do not see any objection. Yet I would like to leave it up to you to decide what should be done; in this case, as always anything you are going to do, will be well done.

There remains nothing else for me to do, but to thank you again, and I cannot repeat it often enough ­ thank you!

Cairo, 16 June 1892

Letter from Louis-Pierre Mouillard to Octave Chanute ­ Missing

16 June 1892

Octave Chanute to Louis-Pierre Mouillard

I started to translate the data on your airplane you mailed me and to make a tracing of your drawings. Then as I thought that your description was not large enough to avoid imitation, I made new drawings on a scale required by the patent office and a rough draft of the patent application so as to cover various interpretations, especially that of the superimposed planes. I sent the entire matter to Mr. Whittlesey asking him to put the application and the drawings in good order to as to get a valid patent, and he answered me that he comprehends the idea and its application. He says that it is very ingenious and that his draftsman is working at it. He is going to send me the documents he is preparing, for your signature.

Mr. Whittlesey asked me whether you made experiments with this machine and with what results. Kindly inform me on this subject. I shall mail you the papers to be signed shortly.

As to your variable pitch propeller, I am waiting for a chance to go to New York to consult with experts in the field of mechanics. Your idea is not absolutely new and perusing Bourne's History of Propellers, I noticed that similar positions have already been under experiment. I think that the weak point of your design lies in the manner in which you propose to adjust the rod which changes the pitch (fig. 7). It cannot come in between the connecting rod and the crank arm, due to lack of space, but hydraulic pressure could be used as the tube for it would require but little space.

The practical realization of this variable-pitch propeller appears to me to be quite a substantial job which would require time and money before results could be obtained with it. But there is a possibility that the mechanics who know what has been unsuccessful, could point out what to do in order to bring your invention to a success.

Let me know which of your inventions you want to be considered first. We have already the lubricator and the airplane on hand, and it is not good to handle too many things at the same time.

16 June 1892

Octave Chanute to Louis-Pierre Mouillard

Mr. Whittlesey writes me that the Patent Office refuses to admit the novelty of your lubricator and points out to us not only the patents of Gregory (303,999) and of Freeborn (429,125) which you already have, but also those of Laval (280,913) and of Owen (212,500) which I am mailing you under separate cover.

The Patent Office tells us the "Gregory's as well as Freeborn's pipes could be applied to the keel without forming a new invention, and that oil could be distributed by means of Owen's pipes without novelty of invention."

We could change our application a bit to get a compulsory patent by way of placing the pipes, but it would have little value.

It seems to me that Owen's patent is the hardest to get around. As he lives in Washington, and as I suppose that he (as most of the inventors) has been unable to get any benefit out of his patent, I asked Mr. Whittlesey to call on him and to find out how much he wants for it. This patent is of no value by itself, but combined with your own and with General Hutchinson's, which I mentioned to you, it may have some value.

We have to go slow with Mr. Owen or else he may get an exaggerated idea of the value of his patent which dates back to 1885. Mr. Whittlesey writes me that he is making inquiries about Owen and that he is going to have an interview with him. I shall keep you posted on the negotiations and I would be pleased to know what you think of Owen's patent.

I believe that in England and in France patents are issued to anyone who applies for them and then let the inventors fight it out among themselves as to the novelties of their ideas. In the United States they try to protect the inventor and no patent is issued unless the idea is: 1: new, and 2: useful. If an inventor has previously conceived an idea which another inventor tries to use in his patent, the latter's application is rejected or else it is properly limited.

Note change of address - 413 E. Huron St.

Chicago, 17 June 1892

Octave Chanute to Louis-Pierre Mouillard

I still owe you the description of my observations of gliding flight in California.

Gliding flight is not exactly new to me. I had already observed the small vultures in Louisiana and in Texas, and I knew that with the help of the wind, they directed themselves in the air without flapping but they usually kept themselves so high that I could not see their evolutions in detail.

The sea gulls of San Diego, on the contrary, are well tamed. Nobody bothers them because they clean the refuse from the boats and when a steamer arrives they assemble to watch the kitchen. The sea breeze blows every day and they make gliding flights at 5 meters from the bridge while waiting for the clearing of the table.

So one can observe them perfectly, measure their speed and that of the wind, estimate the angle of attack, and observe their slightest movement: at eye level, above, below, while flying away, in full flight, equilibrating themselves, and in resting. One sees their eyes, their claws, and the least little piece of down that quivers in the breeze.

My best observations have been made from three bridges of the steamer docked at the wharf. The distance was from 30m to 3m from the wharf and the sea gulls made a half turn at each end.


The wind blew at an angle of 30° with the speed of 5.74 m per sec, and the birds glided without flapping at a speed of 3.05 m per sec relative to the boat, but of 8.02 m per sec relative to the wind. It means that at the angle of 30° the speed of the wind was 4.97 m per sec, and that of the bird 3.05= total 8.02. The angle of attack was 5-7° above the horizon. The birds weighed about 1 kilogram and presented a shadow of 0.18 square meters. Their wings were arched below and, when a rain would come, they either balanced with their wings or they carried their head in front, in back, or sidewise, or in grave cases the feet generally folded under the stomach, or they went down to the wanted angle to reestablish the compromise equilibrium.

It is very probable that for larger birds the equilibrium is much more stable; but I was very much struck by the nearly continuous efforts that the sea-gulls made to maintain a good line under the buffeting of the wind. These efforts are nearly impossible for a machine without living guidance. And I asked myself whether an automatic arrangement could be developed to redress without intervention of the individual the irregularities of an aerial flight.

Here are my observations on the maneuvers that I have seen made by the sea-gulls.

The Departure (Takeoff)

They leave from the water or from where they perch. If it is from the water, they put their beak to the wind, jump into the air, and begin to row vigorously against the wind, advancing nearly horizontally. The flappings are very ample and of three per second, but after seven to ten meters the amplitude is less and the flappings go down to two, and then to one per second, the bird rising at an angle of less than 45° to about 10 to 30m above the water. This elevation that needs a course of 50 to 70m permits him to enter into gliding flight with an acquired speed of 6 to 9 m per sec.

If they are perching, and they seem to prefer to pose themselves on the roof or a pile, the effort of departure is much less and can be made without flapping by throwing themselves toward the water until the gravity gives them a speed of 8m per sec, at which they can elevate themselves on the flight and start to glide, if the wind blows at 5.74 to 6.26m per sec.

If the breeze is regular and of 7m per sec, the bird can leave even more easily from the height of a roof or a pile. He goes with the beak toward the wind, opens his wings very wide but a little inclined below the horizon at the front edge, then changing suddenly this angle of attack above the horizon, he rises while flapping against the wind. So he arises from 0.60 to 1.00m, but nearly at the same time he goes down 1-2m, and then he changes his angle of attack again downward, plunges into the wind, and is now in full gliding flight.

All these maneuvers are perfectly comprehensible; the bird tries by flapping or by falling to give himself a speed over 8-9m per sec, and if the wind blows from 5.74 to 7.00 m per sec he does not need much effort. He can travel broadside or windward at different angles of 30° to 60° with the wind or rise in turning around when the wind is feeble to head himself so as to utilize the acquired height and go where he wants. When the wind is too feeble, he either stays on the perch, which is preferable an isolated wharf "where one can walk and talk with one's friends" or he flaps with a speed of 9-10m per sec. All these speeds have been measured exactly.


The gliding is most often horizontal; the bird does not seem to want to get away very far from the place he surveys, be it a boat or the water. He generally glides at 10 m from the water and from time to time launches down to catch a morsel. I have been able to see these maneuvers from very close when he goes down and when he goes up, but most of the time he is obliged to make some flaps and that would not interest you.

But I have seen some curious evolutions at San Francisco. The sea gulls follow a steam ferry boat in gliding and catch in their flight morsels of bread thrown into the air. Of 70 morsels, they caught 53 in the air and you may imagine the acrobatics that resulted.

A great deal has been said about the ascending winds, and with a wind rising from 6-10° on the horizon, one can do mathematically everything one wants with a bird. I wanted to be sure of that, and I found out in throwing small pieces of paper on the bridge of the steamer of which I told you that the wind was slightly ascendant on the side from which the wind came. I also found out that when the breeze was feeble the birds glided preferably with the wind at the side of the coal shed of 200 m long to 10 m high, where there must have been an ascending wind but that, when the breeze was of 7 m, they went everywhere indifferently. I concluded that the ascending winds helped the bird when the breeze was feeble and when he made certain strange maneuvers like those of the eagle advancing and rising against the wind (p. 22) but that the ascending winds were not at all essential to gliding flights.


I have already touched on equilibrium. It seems to be that birds are accomplished acrobats. The angle of attack changes continually with the needs of flight, and by this same token, instinct changes continually the lifting surface, the position of the head and the feet, to make the center of gravity coincide with the center of pressure. I have doubts about the spring with the little spacing and I ask you (1) to explain it more fully, as I have doubts on the subject.


The bird stops his impetus, if not in sailing at least in ascending against gravity by opening his wings very wide, throwing himself toward the back at an angle of about 36° and pushing back the air against the wind. He is stopped, he balances a moment about 1/2 m from the perching point, and he falls on it nearly vertical. That is a maneuver very difficult to reproduce with an artificial machine and it seems to me the problem of the landing is one of the most serious one to be resolved if one has no flapping or rotating surfaces to flutter a moment as the bird does when his impetus is not sufficiently arrested.

Soaring Flight

It seems certain to me that some birds can perfectly well gain from the wind, if it sufficient for their particular conformation, their weight and their surface, all the motive force necessary to takeoff, to spend the day in the air, to ascend and descend, to go sidewise, and to return home without a single flap.

In order to reproduce this flight is as nearly indispensable to explain it physically, for the danger is great if one neglects one single element. I think I understand takeoff, equilibrium, and landing, and I am able to demonstrate them mathematically although the latter two are very difficult to reproduce with a lifeless machine. I am not sure, however, that I completely understand gliding. It seems to me that the impulse is received when the bird presents a side to the wind just as in the broad side of our ice boats that tack across the ice "in the eye of the wind" with a speed of 100 km per hour, when it blows 35 km per hour. I think that with the wind in the rear the bird descends a little to maintain its speed greater than that of the wind; without that he would not be supported, and that with a head wind he ascends in consequence of the composition of the two speeds (one of the wind and one of its own) but that he loses a little of this latter speed.

I still ask myself why some birds are able to soar and some others of the same size do not at all. Why, for example, our turkey buzzard is a good glider and our wild turkey is not. This latter bird can glide using the acquired speed but it cannot borrow this speed from the wind. It seems to me that it must depend on the form of the wings and especially of the lower front surface and that with the plane surfaces which you propose you will not reproduce gliding flight; that there will not be "aspiration." The sparrow hawk, the turkey buzzard, and sea gull, the three gliders that I know, have the wing curved below making a hook

while the wing of the turkey has simply an enlargement that contains the bone and the muscles.

(2) Please tell me your observations on this subject, and tell me what form you propose for the front of your airplane and the lower surface. I believe that is of prime importance.

I seem to see mathematically that, if the fringe of the wing is curved into a hook, the horizontal component of pressure will be directed toward the front just as if a plane wing were inclined to the horizontal; if that is so, a wing of good curvature can be placed above the horizontal, create lift and, at the same time, "the aspiration." I am about to make experiments on this subject.

(3) Have you written the article for the Cosmopolitan? Please answer especially questions (1), (2), and (3).

Cairo, 1 July 1892

Louis-Pierre Mouillard to Octave Chanute

I herewith enclose two letters which I received from Paris in reference to my book. According to Mr. Hureau de Villeneuve, I could do the proofreading myself, the shipment back and from of the proofs would cause a delay of only twenty days.

I have to write him again to ask him for the address of a printer outside of Paris who could do a le s expensive job. I am also consulting the Bottin * about the price.

I am still waiting for the report of the observations you made during your trip to the West.

*Bottin is a general Directory wherein may be found all sorts of valuable information about the residents of the city; their home and business addresses, office hours, and, apparently, their printing rates.

Paris, June 24, 1892

Abel Hureau de Villeneuve to Louis-Pierre Mouillard

I received yours of June 11 in which you asked me to take care of the proofreading of the book you are about to publish.

A few years ago I would have accepted your proposition, but now I have little time for aviation in order to devote myself solely to medicine. Well, you know that the medical profession is very engrossing and leaves very little time at ones disposal. Therefore I lack the time necessary for reading your proofs. The work would be poorly done and you would have reason to be reproachful.

It would be better if you select a young man, or better yet if you have the proofs sent to you to Cairo. The expense for postage would be easily recovered by the savings you would make in this way.

It is certain that it would be more economical for you to have the printing done at your own expense. As soon as you have the money ready you could get in touch with a printer outside of Paris who would charge you half of what you would have to pay to a Paris printer.

Very truly yours, Abel Hureau de Villeneuve


G. Masson
Libraire de l'Acedemie de Medicine
120 Bould St. Germain
Paris, June 22, 1892

Mr. L. P. Mouillard

Dear Sir,

Enclosed please find the statement you requested. I have gradually reduced the money to be paid in advance and owe you now 10 francs. Below you find the estimate of a volume of 300 pages without illustrations similar to the first one and to be printed in 500 copies. But be it well understood that this is not a contract but rather an estimate. (Signed) G. Masson

Estimate of a volume in 8° of 320 pages (20 signatures) similar in type, print and paper to L'Empire de l'Air - printing 550/500.

Composition of one signature, printing of 500 - paper and glazing ­ 62 fr..
There will be 20 signatures at 62 fr.1240 fr.
Cover in 2 colors46 "
Stitching65 "
1351 fr.

This price does not include the picture which would cost from 10 to 20 fr per page according to its size, neither proofreading, nor annotations, if there are any. It would be well to figure on a total expense of about 1500 francs.

Paris, 2 August 1892

Dear Sir,

Our colleague Dr. Hureau de Villeneuve must have told you that at the meeting of the S.F.S.A. on July 7, I agreed to correspond with you and to do the proofreading of your new book on L'Empire de L'Air.

Various other obligations, especially the signals for aeronautical use which have been put in operation on July 10, by means of the Electric Semaphores of the Channel, prevented me from getting in touch with you earlier. I do it now by sending you under separate cover a pamphlet titled Air-Navigation in 1899 and this sample of my very poor handwriting.

Booth, at least, may show you my love for "aeromania" (aeronautic hobby) in which you have taken such an outstanding place, also that I may do as a proofreader, at your service.

I shall do this work without remuneration. All I ask are two unreasonable requests, as follows:

1.) That you would be kind enough to present me with a copy of your L'Empire de l'Air.

2.) That you allow me to add to your new book a commentary as Captain XXX did to Dr. Marcy's book on Le Vol des Oisseux (The flight of birds), 1880. This supplement will be titled "The laws of aviation" and when printed will have about the same size as the pamphlet I am mailing you. Printing expenses to be paid by you and I shall surrender all other rights of authorship. In case I should get the foolish notion to have a separate printing of it made, this would be at my expense.

With this appendix we could have some preliminary remarks either by Dr. Marcy of the Institute or by Mr. Jaunsen of the Institute and I have the fatuity to believe that your book would not be impaired by either one. Hoping that such a presumption does not leave an unfavorable impression of me in your mind, I am

Very truly yours,
Ch. Labrousse Lt. of the French Navy retired
Member of the permanent civil
committee of Aeronautics, etc.
25 Avenue de Friedland

1 July 1892

Octave Chanute to Louis-Pierre Mouillard

Enclosed please find a translation of a letter which Mr. Whittlesey received from Mr. Owen whose patent for greasing ships while in motion by means of air I mailed you.

Evidently Mr. Owen indulges in illusions and we shall have to pass him up and take out the best patent possible for your invention, with view on previous patents.

I shall be glad to get your opinion on this subject and some suggestions on the best way to follow. As I have already pointed out to you from California we have to expect a more or less long struggle before success may be realized.

I am busy to get from General Hutchinson, of whom I have told you, ownership of his patent for the United States. He keeps the French and English patents.

P. S. I received your letter of June 16 and I shall answer within a few days.

Washington, 27 June 1892

Mr. C. P. Whittlessey and his client


I have your letter of June 15. Yes, I still own the patent for greasing the hull of ships and I appreciate perfectly the importance of my patent and my invention. I have made experiments and have had some letters about them also an interview with the owner of a similar English patent. A famous designer on the Thames River has also made some successful experiments and says to have obtained 30 miles (4 kilometers) per hour.

At present I am preparing drawings for a high-speed boat for New York and the patent may have a great value for this object.

May it suffice to say that a single series of experiments have been made in this country with an open pipe in the rear, and that my experiments have been the first ones with an enclosure parallel to the keel which distributes air all along the ship.

My experiments have a value independently of that of my patent.

As to that value, if there is a chance to reach an agreement it would be better if your client made me a proposition at which I would not mind at all to ask for any price before having gotten results of my actual designs.

I thank you for your inquiry and hope to hear from you again. Very truly yours, Fred D. Owen

4 July 1892

Octave Chanute to Louis-Pierre Mouillard

I received your kind letter of June 14 and I think that my letter of June 17 should give you a better explanation than that of May 20 of what I wanted to say by asking you whether you figure to create suction with surfaces which are flat underneath, without losing altitude.

If I am not mistaken, the master, the bird, does it with slightly concave surfaces. However if you have made experiments which show that suction is possible with entirely flat surfaces, I kindly ask you let me know the results.

Moreover nothing is easier than to get concave surfaces. All there is to know is which is a good curvature and the best way to get it. If it is done simply by means of the wind pressure, I think that the structure of your wings should be modified so that the main arm is at the leading edge.

My letter of June 17 must have shown you that I have no doubt whatever of the possibility to reproduce gliding, but wish to know only of the conditions under which it may be done.

There is another point about which I want to talk to you. Should not the airplane have a speed of its own in order to advance against the wind? I am uncertain about it. Your eagle (page 22) took off by dropping two or three meters. The gull which I described to you started to draft when rising from the pile at the beginning of its flight, which is easily explainable as being due to the disintegration of forces. D'Esterno and Capt. Lebris said that a preliminary impulse is indispensable. I imagine it is similar to flying in spirals, because with the wind in the rear the speed should be high enough to create lift by means of a relative speed which is the difference between the speed of the bird and the wind velocity. But with the wind ahead could the airplane rise and move forward at take off?

It seems clear to me that it could rise while drifting then plunge into wind and so get a relative speed with which it could rise again and glide; but this is a delicate maneuver.

Yet something else: As a ratio you gave me a load of 5 kilograms per square meter. This is a good ratio for cross country which may even be reduced to 10 kilograms per square meter for high speeds. However arrangements cannot always be made to land in water. For a parachute landing there should be at least a surface which is loaded by 1.25 kilograms per square meter. What ratio do you recommend for the experimental airplane?

I shall keep on sending you my articles on experiments which have been made, and while preparing them I have read with great interest all patents I could get of machines of which Dielaide's illustration gives a very imperfect idea. Almost all inventors consider two kinds of control and most of them propose a tail with variable angle for vertical control and a control surface below the tail (which the illustration does not show at all) for horizontal control. I believe, for the latter control, your proposition to be far superior to the other control surfaces, but I am not absolutely certain whether safety does not require a tail with variable angle to act as an automatic control surface of the airplane. I believe the soaring bird uses its tail as well as forward and backward motion of its wing tips which you have reproduced, so well and which I consider as one of the most successful characteristics of your machine.

D'Esterno proposes something similar. In the first edition of his book he presents an airplane, the wings of which rest on a pivot in front to allow them to be moved forward and backward; in the second edition this design is omitted and it seems that in his patent he found out that this motion is too difficult to reproduce, because he did not patent it at all, a fact for which I sincerely congratulate you.

D'Esterno's machine was meant for gliding, but in his patent he gave in to prejudice, and having placed his wings on two shafts which made it possible to bring them in a V position he spoke of the possibility of flapping wings, without referring to an engine whatever.

Du Temple's machine had below the tail a control surface with an independent motion. The machine was equipped with an engine, but Du Temple was also thinking of gliding. The wings could be moved forward or drawn backward by letting the rods which were attached to the nacelle slide one below the other. However this could not be done while the machine was in motion.

As to your book, do I understand correctly that your loss on L'Empire de L'Air was 2400 francs or that this are the printing costs which were reimbursed to you by the sale of the book. I am willing to advance the printing expenses as soon as your interests are covered by patents, but the new book should bring in its initial cost. At any rate get all the information necessary and let me have it. However, I think it would be better to have some sketches in the text so your ideas are better understood.

I am sorry that you have approached Mr. Hureau de Villeneuve. I believe him to be very jealous of everything which does not come from his shop.

If you have a chance, have my articles on the airplanes translated. You will find in them some strange tales of experiments which have been carried out.

Cairo, 10 July 1892

Louis-Pierre Mouillard to Octave Chanute

Here are the answers to the questions you asked me.

As to the lubricator and the decisions to be made on this subject, I kindly ask you to do the best you can. You know I rely entirely on you, and anything you do will be well done.

You may tell Mr. Whittlesey that I have experimented only with a small model of this airplane. I have seen this one-piece wing system in operation on the puffins and the swifts.

In reference to my propeller I kindly ask you to read the chapter again when your mind is relaxed, if possible in the country where you will be free from care. I think you will better appreciate the organ which actuates the wind because I believe you will find out that there is the trouble. I think you are going to change your viewpoint. You ask me what I want to have patented first. Answer: Anything which may be quickly transformed into money. This would enable me to meet you as soon as possible, so that I could explain to you orally those matters which are not so easily understood in letters, as one hour of conversation is worth more than a written volume.

In your letter on aviation is a question which puzzles me and I want to answer it first. I do not know the Cosmopolitan Magazine and I did not write an article for it. Besides I only write to you on aviation. You would greatly oblige me if you could tell me more about this article and if it is worth while to be kind enough to send it to me.

Let us pass on to the airplane. Naturally, the spring alone is not strong enough for the completely automatic adjustments for vertical equilibrium. Unquestionably it could not move the wing tips forward by itself; it therefore should be allowed to react without being forced either by the hands or the feet so as not to require more power than necessary to move the weight forward by letting it act freely in its own fashion. Left to act by itself, it will assist the maneuver in a precise manner and will succeed in giving the necessary angle at the right moment. For the opposite motion (the wing tips are somewhat forward, kept this way by the ropes that are actuated by the legs and the hands, because a wind of 10 meters is to be overcome); if in this position the airplane unexpectedly strikes a rapid wave, let us say one of 15 meters, the spring will automatically produce the useful angle. When this wave has passed, the craft will again automatically take the position for a wind of 10 meters.

This spring of a well calculated strength will be a great help in the production of vertical balance. I do not dare with all discretion to assign to it a more important function than the one just indicated, but I believe it to be a device that will produce more than I indicated. The bird, moreover, possesses it; it is again a copy, simplified it is true, but I could not find a better one unless I entered into complications that a trial airplane could not utilize. With the bird there are springs that oppose deflection; they are the series of muscles that extend from the wings and a counterspring designed to stretch the skin that unites the arm to the forearm. It is this counterspring that produces the curving of the front of the wing; curving that has made all the aviators dream so much and of which I am certain one can get along without, as has been proved to be by the thousands of airplanes large and small that I have seen function,

Moreover, I propound herewith a principle that is not in my book but over which I have been pondering for years, namely: The less hollow the wing is in its active part (the hand), the longer the flight will be. May I assure you that I have studied this problem carefully. Besides I am going to write a paragraph on this subject to be added to my book because this subject is of great interest. As I do not think you are in a good position to study this ornithological problem, I kindly ask you to take my word for it, and I assure you that I am not mistaken.

From theoretical considerations, this curvature is of little interest. A flat surface and a curved surface function in almost the same manner. In the curved surface, pressure and suction are equal. On the flat surface, many knotty problems caused by transient pressures are somewhat troublesome, especially when the surfaces are very large and the speed is very high. But this question belongs entirely to the highly developed stage of flying and is unimportant in our case. Considered from a practical viewpoint, however, the matter is entirely different. When at rest, the wing should be as follows:

Section at the center of the remiges

This arrangement is indispensable, as my experience has proved. When after careful consideration and after studying the large birds, I proceeded to build a large wing whose section at the remiges was:

I made use of a good wind to try its action. The wind showed me at once that I was wrong. The front made a beautiful plunge that, when properly considered, was natural. The surface between 1 and 2 was exposed to a pressure and this pressure deformed the wing tip in proportion to its moment, because it is hard to make this tip rigid; in short, the aviator would have taken a header if the craft had been manned, I had given in to the common belief and pure theory had created this masterpiece. By a reconsideration of the situation, a conclusion is quickly reached that this plunge must be prevented by all means and that, on the other hand, a constant lift must be created. This lift may be obtained by the manner I have previously stated. Next, I examined the large birds and I noticed that when they are at rest (I am assuming that the remiges are clipped 2 inches from the tips):

Great horned owl

Large vulture

when under pressure (the feather under the weight of the bird and under stress) produced the following arrangements:

As you may notice, the loaded wing becomes a horizontal surface, or a series of horizontal surfaces which is the same thing.

I come now to the impression expressed throughout your letter that there is a lack of the power of action. These acrobatics frighten you. Man will never be nimble enough to produce them. You reasoned that the bird is endowed with this agility and the aviator is not.

This impression, which I consider to be perfectly correct, was imparted to you by the species of bird you studied. According to what you wrote me, you observed the gull and the turkey buzzard. What is the latter bird? Probably cathartes aura or cathartes urubu; it certainly is one or the other. I know the structure of these small American vultures; I observed some ten of them at the Jardin des Plantes (Botanical garden) in Paris.

They fly well but are by no means experts in the type of flight which I extol. These birds weigh less than 1500 grams; this mass is not sufficient to produce the effects of penetration and stability of which I speak in my two books; furthermore they lack the aptitude for such a flight. If, instead of these three larks you could have seen the condor for only five minutes you would be enlightened with the truth of what I have described.

As you probably do not intend to return to California within the near future and as it is however necessary that you convince yourself that I do not exaggerate, resort to experiments. Make 4 or 5 airplanes which have a span of 0.50 meters, 1 meter, 2 meters, 5 meters and 10 meters. As soon as they fly correctly in still air, let them fly in turbulent air and you at once will have the desired demonstration.

You will notice that the small airplanes are being upset, deviated and pushed back by the air current; you will understand that, in order to keep them on the correct course, they must have more activation the smaller their mass. On the other hand you will see how the large and heavy airplanes move majestically in the direction they have been launched, showing by no motion whatever that they are affected by the action of the current; in other words they produce the quiet imitable flight which I have described as being that of the great vultures.

For this reason I urged readers again and again to study the very heavy birds in order to be convinced of the possibility of reproducing their flight. I expressed this on pages 217-8 and at the end of page 73 and in many other passages. I even say that a bird weighing less than 2500 grams should not be considered for observation because it tends to show that in order for flight to be accomplished there is required a sum of expendable energy which one can not dream of producing.

25 July 1892

Octave Chanute to Louis-Pierre Mouillard

Enclosed find application, description and affidavit to be executed (same as the last time) for your airplane patent. Please return them to me as soon as possible. I also am sending you 500 francs for outlays which you may have to make.

In order to make a good description Mr. Whittlessey has put in some time. I have made a literal translation of it for you, hoping to give you in this way a more exact idea of it; but I notice that I made an atrocious job of it and would have done better by adhering less to the wording. If there are some obscure points, please have it translated from the English.

Please indicate with pencil on the English text of the description the changes and amplifications you wish to make and I shall have it rewritten by Mr. Whittlesey before delivering the papers to the patent office.

The important matter in an American patent is to claim exclusive propriety of everything new in the invention. Mr. Whittlesey has enumerated 24 claims which have to be fought out with the patent office. I doubt whether we may obtain the three provisions, but we shall see.

30 July 1892

Octave Chanute to Louis-Pierre Mouillard

I received the English patent from General Hutchinson who cedes to you the rights for the United States. He is willing to sign the necessary papers provided that this translation does not involve any expenses on his part. However, he wrote me a letter, dated July 15.

"I received your letter of the 2nd, and according to your request I am pleased to send you my "specification". Yet I warn you, as a friend, not to venture any money in this enterprise, unless you could add some chemicals to the oil in order to prevent the formation of algae.

"I have given up all hope of success. One of my sons who took part in the aquatic sports at Oxford University told me that they often tried out boats with greased hulls without any better results.

"Admiral Scott a well-known mechanical engineer who invented the carriage for large guns, was very enthusiastic about my idea. He had it tried out by his son who owns a yacht; but the test was a complete fiasco.

"After all this seems logical to me, when one recalls that a drop of water which falls on a wet board will run down when the board is inclined, but on a greased board which has the same inclination it will adhere."

Very truly yours, etc.

It has to be found out whether the General is right. He says in fact, that the coefficient of friction of water on water is less than that of water on oil. I do believe this; but is the coefficient of water less on iron or on wood in their regular state than on the same materials when they are oiled? This has to be established and I am going to go to New York in the near future to learn more about the results of experiments a friend of mine is making this summer.

At any rate I would like to have your view on this matter and to find out whether you think it would be better to give up the idea to take out General Hutchinson's patent in the United States. Besides it is the same as the one for which we have made application in your name with the difference that he puts his pipes vertically and flattens them out to decrease frontal resistance.

2 August 1892

Octave Chanute to Louis-Pierre Mouillard

I found your letter of July 1 when I returned from the country. I shall lend you an amount to the extent of 2500 francs for printing your book, against your note to become due in one or two years at 5% interest. I believe that the sale of your book should realize the necessary amount.

I think Mr. Hureau de Villieneuve gave you a good advice when he told you to have the printing done outside of Paris and to proofread it yourself.

As to the illustrations I urge you to insert all which are necessary to make your general ideas well comprehensible. It would not be right to spoil a book in order to have a little money; besides, it would hurt the sales. I also advise you to print 5000 copies; this would cost paper and printing only, and I believe, with the impression your first book made, you should be able to dispose of them.

Concerning the number of pages, I would not try at all to fill 320 pages. At my opinion it would be best to tell all you have to say about flight without flapping wings, and then stop.

Furthermore, I would advise you to fix the sales price higher than usual. You are dealing with a special and limited public, and those who are interested in the problem will pay 7.50 francs or 10 francs just as likely as 5 francs. However, I confess that the opinion of a bookseller would be much better than my own; but ask one because if you have the book printed at your own expense you would not be able to allow the dealer much of a discount. I estimate that the copies will cost you 3 francs each if you print them in lots of 500, and less than 2.50 francs in lots of 1000. You should be able to sell the book to dealers for 5 francs.

Because the aim of this book is to make known your ideas of gliding flight, it would not be prudent to publish them before the patents for which we apply have been granted. So please let me know in which countries you think it advisable to apply for a patent on your airplane.

It will take all of six months to have a patent granted in the United States, but we may retain the secret for six months more, as I explained to you. Before going into any expense in other countries, it would be a good idea to make some tests, to be sure that you are not mistaken, and also that the machine will not only rise but will move forward. I consider this feat to be possible, but please answer this question: Did you ever create suction without preliminary propulsion on a model or any machine whatever?

I also kindly ask you to give me any information you think to be useful, so that I may proceed with experiments on the airplane.

9 August 1892

Octave Chanute to Louis-Pierre Mouillard

I received your kind letter of July 10 and mailed you three copies of the Cosmopolitan Magazine which contain some articles on air navigation.

This magazine devotes itself to this subject and has requested me to contribute some articles. The proposition had been broached to ask you for one on gliding, and I understood, according to a letter from the editor of March 23, that he had already written you. I do not know why he has not done so, but I am going to New York shortly and will get some information verbally. The magazine pays from 250 to 500 francs for an article of from 3000 to 4000 words and prefers that it includes some illustrations.

As to the conversion of your inventions into money, I am afraid that this will take quite some time. Everyone of them has still to be applied practice, and sometimes it takes years to develop an idea into a new machine. As a start I selected the lubricator because it looked to me to be the most simple thing and yet you see that it is not as simple as it seemed to be. I may have been wrong and I therefore ask you again to tell.me which invention you think may be converted first into money.

It seems to me that your best bet is the airplane I am willing to spend some money to experiment with it; but first of all I want to get a clear idea of the results to be expected. Right now I think you are wrong when you say "that the curvature in front could be dispensed with" because all my experiments with flat surfaces showed that they rise backwards. Yet I would like nothing better than to be convinced to the contrary.

You have a somewhat wrong impression about my idea of the power of action of man. I simply believe in the necessity of having an airplane of a more stable equilibrium than that of birds, because the pilot must give all his attention to control.

You refer to experiments to be made with airplanes of a span of from 0.50 meter to 1 meter and 10 meters. Will you kindly give me some instructions of how to build them properly. I do not understand very well the "correction fold."

19 August 1892

Letter from Louis-Pierre Mouillard to Octave Chanute ­ missing

1 September 1892

Letter from Louis-Pierre Mouillard to Octave Chanute ­ missing

12 September 1892

Octave Chanute to Louis-Pierre Mouillard

I received your letter of August 19, which contained your patent application and I forwarded the letter at once to Washington; at the same time my letter of January 17 has been returned to me from Cairo, marked "Unclaimed".

There is evidently some carelessness on the part of the Cairo Post Office and it would be better if you would give me a more definite address, if this is possible.

As there is a possibility that some more of my letters went astray, I herewith give you a list of those I wrote you since January 1, 1892.
Jan. 16Experiments with the lubricator in New York, etc.
Jan. 17High speed train etc. - enclosures
Jan. 27Ms. to Mr. Langley - Patent for airplane, Hutchinson's lubricator. etc.
Jan. 31Mailed you application blank for the lubricator patent.
Feb. 11En route to California ­
What inventions do you want to have patented, etc.
May 20Acknowledged receipt of airplane drawings - suction
I also wrote you from California but I do not remember the date.
June 16Question asked by Mr. Whittlesey, etc.
June 16Difficulties to get the lubricator patent
June 16Report of my observations in California
July 1*Difficulty Owen about lubricator
July 4*Suction with flat surfaces; is preliminary propulsion necessary?
July 25mailed application for airplane patent
July 30Hutchinson's patent, etc.
Aug. 2*Publication of "Vol sans Battement"
Did you create suction with a machine?
Aug. 9*Cosmopolitan Magazine. Various inventions ­ Conversions of them into money? Experiments to be made.

I have no reply to those marked with an *.

I am returning to you Mr. L's sugar-coated letter and I warn you not to enter into any business relations with him. I was told in Paris that he is one of a small group which lies in wait for somebody else's ideas. Let the correspondence slowly come to an end and never tell him that you intend to apply for patents in case the preliminary experiments are successful. Yet you may tell him that Mr. Langley has your book at present and, as he is in Europe, you cannot get it back until he returns home.

1 October 1892

Octave Chanute to Louis-Pierre Mouillard

You wrote me several times to have the patents issued in both of our names, but Mr. Whittlesey thinks it would be better to take out the patents in your name alone, as original inventor, and afterwards you cede to me half of them, according to our agreements.

I am enclosing agreements for the patents of the lubricator and the airplane, together with a translation of the latter. These agreements have been prepared by Mr. Whittlesey. They are in duplicate and you are to keep one and to send me the other after having it signed and notarized by the U. S. Consul.

I did not receive any news from you since your letter containing the papers for the airplane, and you owe me several answers. I am going to New York soon where I intend to devote myself to your log and your propeller.

TRANSLATION ­ Agreement concerning the airplane

Whereas the undersigned, Louis P. Mouillard, citizen of the French Republic, residing in Cairo, Egypt, has invented certain new and useful improvements in the methods of air navigation for which he has applied for a United States patent on Sept. 4, 1892 the order number being 416,786, and whereas Octave Chanute of Chicago, Cook County, State of Illinois, desires to acquire a part in this invention and in the patents which may be obtained for this machine in the United States as well as in other countries.

Therefore this agreement affirms that in consideration of the sum of one dollar legal tender of the United States of America, received by me and also in consideration of the fact that said Octave Chanute is to pay all official taxes and fees and all expenses for legal services rendered necessary to obtain said patents, and each of which in accordance to these expenses to be made, I, the undersigned Louis P. Mouillard agree to assign, sell and remit to said Octave Chanute, his heirs or representatives a joint half of my entire right, propriety or interest in said patents for the United States, as soon as it is issued, also in the patents of all other countries when they will be issued, agreeing to sign all papers necessary to invest the said Octave Chanute, his heirs or representatives with the title of the above mentioned joint half of the invention and of the patents.

Above all I agree that this agreement shall be binding for my heirs administrators or representatives.

In testimony whereof I affixed my signature and private seal.

Cairo, 8 October 1892

Louis-Pierre Mouillard to Octave Chanute

I herewith confirm my two registered letters of Sept. 20. I received your kind letter of Sept. 12, also that of January 17t. I checked the list you sent me and find only the latter missing.

I can not give you another address, because the streets, for the most part, have no names, yet there are letter carriers who deliver the mail to the homes. It is unnecessary to tell you that I complained in a way that a similar error will not happen again.

Generally the mail service is rather accurate, during five years while I was director of a large commercial house I received several letters a day and none ever went astray. The letter mentioned above was delivered to the Cook Company, probably because it came from the United States, and there are many American tourists on the Nile.

I am going to answer your letter which went astray. You do not want to believe that, in order to move successfully, the long side should be in front. Yet, I have tried to make this comprehensible, but nothing is better than a direct proof. You could make this test easily. Build a plain boat, i.e., a simple piece of light wood which is shaped according to the plan I propose. After this shape has been produced, varnish the wood ballast, so it floats a little, by means of a metal keel which will hold it in a good position in the water, then launch it in the water so that first the long side is in front, where at my opinion it should be, and then with the long side in the rear and compare the distances which have been covered. It is evident that the water and the same manner of execution should be sufficient for both experiments. This is very easy, you may have access to some body of water, a well shaped piece of wood, 1 meter long, should demonstrate the difference of the penetration capacity. As to the observation of objects intended to cut through water or air, look attentively and you will see that I am right; but I admit that observation is infinitely more difficult than experiments. Therefore you should devote yourself to the latter, in order to convince yourself.

When you are convinced you will have faith: in the high speed rail road, in the boat, and in everything which has this shape. You will then notice also that all modern ship designs proceed slowly toward the mass to the rear so that in order to cut through fluids successfully a long front is required, and that this is the way to do so. You then believe the prophet who never experimented himself because his means did not allow it, but who instead watched the experiments of the "master mechanic" (nature) and benefitted from its manifestations. I have seen creatures which are so fast in the water that the fishes look like unanimated floats which do not seem to move. I saw how this paradoxical creature was built and from this study I copied the shape which nature prefers for swift motion. If I am wrong, I am in good company. As you see, dear sir, I probably am right, so convince yourself by means of this little experiment.

Now I come to the airplanes. Here also you give no kind reception you do not believe completely because you have not seen, and here also palpable proofs are necessary.

I think it would be well to convince you of the gliding capacity by sending you something small which should make you ponder. It is a small paper airplane I have built and which I am going to send you by parcel post. I hope it arrives undamaged. If so you may note that it has a gliding angle of 10 degrees (in a room). At the same time I shall give you directions of how to use it.

In reference to my two last letters, my torpedoes, I recommend them to your consideration. I kindly ask you to give them your full attention. This is a serious work which, without impertinence, should not be treated lightly

P.S. Thanks for the information of Mr. L. ­ I acted accordingly.

23 October 1892

Octave Chanute to Louis-Pierre Mouillard

On my return from New York your letter of Sept. 1st was awaiting me, also the letter which contains a description of your torpedo. I shall take this matter up with you after I have examined it with all the care it deserves.

Mr. Langley whom I have seen in Washington is at present preparing a summary of L'Empire de l'Air which he expects to publish in the collections of the "Smithsonian Institution" and for which he intends to remit to you 250 francs. I have accepted his proposition in your name. Perhaps he will do likewise when "Vol sans Battement" is published.

Mr. Walker the editor of the Cosmopolitan Magazine, of which publication I have sent you several copies, authorizes me to offer you 300 francs for an article of about 4000 words on the flight of birds, and some illustrations to go with it. You could either compose this article from excerpts of your two books and I could translate it or you could authorize me to translate a part of Vol sans Battement.

Yet I think it would be better if you would write an article of unpublished facts to rouse the curiosity of people who do not know anything of gliding, and furnish about 6 to 8 illustrations with it, the most startling ones would be the best. They could be either drawings or very distinct photographs. You will then see in the magazine with how much care they are engraved.

In one of my letters I asked you for an address more particular than General Delivery so that no more letters are returned to me. Mr. Langley is of the same opinion so he can mail you the 250 francs. He says that he does not like to take anything away from people which belongs to them, without compensation, even if the law would be on his side if he would not pay for it.

Cairo, October 28, 1892

Louis-Pierre Mouillard to Octave Chanute

Enclosed are the signatures attested by the Consul General of the United States. I believe that I am about at an end with my correspondence. I hope that my last letter arrived before you left for New York and that you could spare a few moments to give it some attention.

As I have no important work to do I entered tho Egyptian Government's Public Works Service which keeps me busy till 2 o'clock in the afternoon. So I have enough time left to go over my book and to think of aviation. Now it will be your turn to write and I will have nothing to do but to answer your questions.

Some of these days I shall send you by parcel post several small airplanes made of paper. One of them has a gliding angle of less than ten degrees but I am unable to send it to you because it is too big for the regulation size package. But there is a smaller one or several smaller ones which I shall send you

Cairo, November 18, 1892

Louis-Pierre Mouillard to Octave Chanute

I herewith confirm my last letter in which the two papers, signed and attested to, were enclosed.

For safety's sake you may add to my address: Rue de l'Eglise Catholique (Catholic Church Street).

At this point allow me to ask you to express my thanks to Mr. Langley for the generosity and kindness he wants to show toward me.

I also ask you to tell the editor of the Cosmopolitan that I am preparing the article on gliding of which he spoke to you, as well as some drawings of birds in flight.

Unfortunately photography is out of reach for me, as a very strong landscape lens would be necessary in order to show the vultures in any other than a microscopic picture. I simply can not afford it, which is too bad because I have some models all ready to pose. As for snapping their picture in full flight, I have been dreaming of a camera that would hunt for them way up at 300 meters, but I can't even think of doing that.

Photography would certainly be an infinitely more exact evidence than a drawing, but for want of a camera one must resort to a pencil.

In your letter prior to the last one you told me that while you are in New York you would find out more about the boat, in your last letter you do not mention it at all; please, what has happened?

I also wanted to ask you when you could return my book so that I could make use of your kind offer to advance some funds toward its publications. I have ny notes but not a duplicate of the manuscript; if I had to rewrite it, I would be quite embarrassed, as I have actually not much time at my disposal.

December 12, 1892

Octave Chanute to Louis-Pierre Mouillard

I received your letter of November 18, just when I was about to write you.

But first, I beg your pardon for not having acknowledged receipt of your letter of Oct. 28 with the two signed papers. However, I had been buried under an avalanche of work, and then I have to inform you of the death of Mr. Hastings, the young engineer whom I mentioned to you at the time when I hired him to translate your book and to make experiments later on.

He passed away recently after a lingering sickness which incapacitated him for one year, and only half of your book is translated. I am going to send you this half at once, and I wrote to Professor Langley to send me the chapters which are in his possession. When he learned that you had applied for a patent he consented to see the chapters referring to the airplane which he had refused to do previously. Within a few days the package will leave here by registered mail.

In regard to the other half I do not know whether it would be better to try and translate it, despite my other work, or whether it would be better to send you the entire manuscript and make the translation from the printed pages. I confess that this book means a great responsibility to me and I shall feel more at ease to know it is in your possession. I have kept it in my strongbox with orders to my entire family to send it to you at once in case I should die suddenly. However, I also cherished the hope to hand it to you personally.

For I entertained the idea to pay you a visit this winter in Cairo when we could discuss some observations and questions which you never answered. (I do not say this to reproach you in any way for there must be a reason for it on your part.) However, my wife is afraid of an ocean trip and as she is in poor health I do not dare to leave her alone. Besides I shall have to battle here this winter with the patent office.

Quite recently this patent office refused to grant you a patent; it says:

"Examining the project presented we believe that the described invention as a whole is not practical, since the machine cannot rise without a balloon. In other words the project is not useful according to the meaning of the law. No evidence will be considered sufficient to demonstrate the efficiency of the project and to cause the patent office to rescind its objection, unless it is a model in full operation which would be capable to make an ascent and to be controlled."

In a conversation with Mr. Whittlesey the examiner said some affidavits could be considered which state that experiments have been made with the invention if the facts were well specified, but even so a small model would be necessary to demonstrate the theory of the invention. Mr. Whittlesey wants to know whether you could supply these requirements. The sooner the better.

I do not need to tell you that this decision is absurd, but it has been made by the authority and must be appealed.

I have already made arrangements in this direction. In my article next month I shall speak about you and I shall go to Washington and take the matter up personally with the examiner in charge. You, on your part, please send me all the data you may have.

You know that in this country the patent office judges the usefulness and the novelty of an invention before granting a patent, while in Europe most governments issue patents to anybody who applies for, and let the inventors clear themselves when involved in a law suit. For this reason it is always better to take out the first patent in the United States.

I was told in Washington that the patent office had been swamped lately with plans for air navigation, every one of them as absurd as the other. This perhaps is the reason for the new severity with which the office acted against you, because it has passed upon very queer cases. If worse comes to worst, please let me know:

1) What do you think would be the cost of a complete airplane?

2) When experimenting in the open, would it be possible to disguise the construction sufficiently so that the idea would not be understood and the machine could be flown before the patent is issued?

In reference to your boat, I presented the proposition briefly to Mr. Mosher, the famous designer of high speed yachts in New York. He was not enthusiastic about it. He said that perhaps it is possible, but hardly practical. However, he consented to examine the matter more seriously. But he does not read French so I shall have to translate the entire description into English and I have not yet found time to do so I expect to make him acquainted with all your maritime inventions, except the torpedo, on which subject I shall write you a separate letter so there will be no mixup among the various matters.

22 December 1892

Octave Chanute to Louis-Pierre Mouillard

I just received the chapters of your book which I gave to Mr. Langley, but I notice that one part of the translation which Mr. Hastings made has not been corrected, so I shall do it at once. This will cause a delay of three days, and today I wish to take matters up with you about your torpedo. I have read your letter over and over again and pondered over it very seriously. The idea is new, ingenious, daring, it may be successful and the results are incalculable. But alas, my dear friend, like most of the inventions you have sent me, it is very hard to cash in on it within a short time, and if I understand it correctly that is just what you want to do, so that you could use the proceeds to realize your airplane.

There is only one interested party and that is the government, and ours is not in the least prospective. The men in charge may therefore take plenty of time to wrangle with the matter and perhaps will not have anything to do with it. However, I am sending your study to Mr. Langley, asking him to keep it confidential and to give us his opinion.

I told you different times that the airplane was your great asset and if it should succeed your other inventions would be more easily accepted. For several months I have thought about different ways to make your success easier and I hesitate among different ways.

You have asked me many a time to make experiments according to the directions you sent me. I have not made any, because in case they should not turn out successfully you may think this is due to lack of care and intelligence and this would cause disagreement between US. On the other hand if I send you money to enable you to experiment yourself before the patents are obtained, the invention may be stolen.

There is still another way which would be to ask you to come to America to conduct experiments, but I am not a rich man. I could set aside 25,000 francs for the experiment but if it should not meet with success I had to stop right there. What would then become of you? would have uprooted you from your house, and I never could forgive myself.

To be able to judge the probability of success is the reason why I intended to pay you a visit in Egypt, why I asked you so many questions about "suction" and why I am impatiently expecting the airplane model you intend to send me. We have in this country a Mr. Lancaster who claims to have produced "suction." However he hides from everybody and has taken refuge in a desert in order to carry out experiments.

I believe you are better prepared than anybody else to succeed in gliding flight but this may take much more time and may be more difficult than you think it is. And then, after all, the wind in the temperate zone is not always blowing at a favorable velocity and the practical application may be limited to countries where soaring birds have their habitat. Write me very frankly your opinion about all this.

Cairo, December 24, 1892

Louis-Pierre Mouillard to Octave Chanute

This letter simply wants to make you remember me and to wish you a happy new year.

I am preparing the article for the Cosmopolitan. I only have the drawings to make. It takes long for I have little time to give to it.

I don't dare tell you that I am disturbed because I don't get any letters from you, but that is the case. But the proverb says: No news, good news, and I have faith in it.

December 25, 1892

Octave Chanute to Louis-Pierre Mouillard

I am sending you by registered mail all parts of your book which have been translated:

Envelope No. 1Introduction
Envelope No. 2AviationUp currents
Flapping wing flight
Flight without flapping wings
Envelope No. 3AviationOn penetration
Envelope No. 4"Suction
Envelope No. 5"Horizontal control
Envelope No. 6"Vertical controls surface
Envelope No. 7"Fixed airplane
Envelope No. 8"Experimental airplane
Envelope No. 9"Engine powered airplane

This is the important part of your book. As the pages were not numbered when I received them, I numbered them with pencil on the bottom of each page; this has been done a second time for one part of the book which arrived later than the other.

I think that when you review the book after the fire of the composition has cooled down, you will make some transpositions and changes in addition to those which you have already pointed out to me, before giving the book to the printer. Do not be embarrassed by doing so, for I know that I have to revise my translation by comparing it with the printed book, before giving it to the publisher here. Furthermore, unless the English publication comprises "L'Empire de l'Air" and "Vol sans Battement" in one volume, several passages of the second book have to be changed so that they may be understood by those who have not read the first one.

In one of my letters I believe I have informed you of my opinion on the subject of the chapter on "suction" which should be written with as much emphasis as possible as it is bound to captivate the attention of the readers.

The part which is still in my possession consists of:

Envelope No. 10Bird studiesPicture Studies
" 11"Liometis Nasicus etc.
" 12KiteKites Sail
" 13BalloonsAlpine-valve, Atmosphere
" 14Parachute
" 15Chuts
" 16The Desert

I shall try to translate it by dictating each part to a stenographer, but I am ready to return everything to you as soon as you ask for it.

You never informed me whether the conditions I proposed to you for the publication of your book are satisfactory to you. My idea has been to put you in a position to realize the possible profits of the sale. However, if you prefer that I take all the risk, I am ready to do so.

On to 1893