Wilbur Wright to Octave Chanute

Dayton, August 28, 1904

Your letter of Aug. 14th received. Also the copies of Knowledge, for which please accept our thanks. Unless Major Baden Powell adds some balancing and steering device to his gliding apparatus, I fear he will have some exciting experiences before he progresses very far.

I presume that it is Mr. Avery's plan to rise as a kite, then cut loose and glide down. If there is time to perfect details and obtain practice the plan would seem to be feasible.

Since the first of August we have made twenty five starts with the No. 2 Flyer. The longest flights were 1,432 ft., 1,304 ft., 1,296 ft., and 1,260 ft. These are about as long as we can readily make on our present grounds without circling. We find that the greatest speed over the ground is attained in the flights against the stronger breezes. We find that our speed at starting is about 29 or 30 ft. per second, the last 60 ft. of track being covered in from 2 to 2 1/4 seconds, the acceleration toward the end being very little. When the wind averages much below 10 ft. per second, it is very difficult to maintain flight, because the variations of the wind are such as to reduce the relative speed so low at times that the resistance becomes greater than the thrust of the screws. Under such circumstances the best of management will not insure a long flight, and at the best the speed accelerates very slowly. In one flight of 39 1/4 seconds, the average speed over the ground was only 33 ft. per second, a velocity only about 3 ft. per second greater than that at starting. The wind averaged 12 ft. per second. In a flight against a wind averaging 17 ft. per second, the average speed over the ground was 42 ft. per second, an average relative velocity of 59 ft. per second, and an indicated maximum velocity of 70 ft. per second. We think the machine when in full flight will maintain an average relative speed of at least 45 miles an hour. This is rather more than we care for at present.

Our starting apparatus1 is approaching completion and then we will be ready to start in calms and practice circling.

1 This is the catapult starting device, first used on September 7 the "derrick" mentioned in Wilbur Wright's Diary entry for that date. The starting apparatus was photographed for the first time on June 23, 1905 (Plate 87).

Octave Chanute to Wilbur Wright, September 5, 1904