“My dear Mr. Chanute:
“I am glad you received safely the report of my observations on bird flight in this region. As I told you, I spent three days in the vicinity of Pelican Island making notes on, and photographs of, the movements of these birds in the air. I hope the report will be of some assistance to you in your inquiry into the problem of ‘soaring birds.’ One thing we all know, and that is that birds do rise or soar at times without any apparent movement of wings, tail, or feathers. How this is done is, of course, a puzzle to us all. Your theory that even in seemingly calm weather, when there is no noticeable agitation of the atmosphere, there may be a vertical column of rising air induced by imperceptible movements of the lower atmosphere, may be the explanation.
“I believe, as you do, that when we have found the explanation of how a bird ascends without the use of its wings, we will have made the longest step in conquering man-flight in the air.
“While it has no bearing on your present line of investigation, I cannot resist telling you that the observations you asked me to make for you have greatly interested me in the subject of aviation in general. Always a dabbler in physics and fond of experimenting, I have been led into working out an idea of my own. While watching the flight of birds, I could not but be astonished at the wide difference between their tail motions and the rear rudder or tail of the aeroplanes as I have observed them in magazine pictures.
“I was so much impressed by this lack of resemblance that I yielded to the temptation to try to adapt the natural apparatus of the bird to man’s artificial flyer. I have even made a small model of a guiding tail or rudder for aeroplanes, patterned as nearly as practicable after a bird’s tail. Of course, I have no means of knowing how such an apparatus will work, but later I mean to send you some drawings, that you are at liberty to utilize as you see fit.
“These drawings will explain themselves. My object has been to secure a guiding contrivance that will not only alter the course of an aeroplane, but will at the same time equalize the darting tendency that I understand always follows a sudden turn to right or left. With it, I hope to lessen the need of flexing the main planes of the machine when the rear rudder is used, a large part of the tendency to dart being absorbed, in theory at least, by the double action of my bird-tail rudder. The moving machine I hope may not only be steered up or down, or right and left, but one motion of the shaft will give the two movements which now must be made independently.”
Here the letter came to an abrupt end.
“I knew it!” shouted Andy. “I knew it was a rudder of some kind. It ain’t all clear to me yet. But one thing is clear enough. I can make a copy of that model. If it works, I’ll finish that letter. But, if it does, the plans of it aren’t goin’ to anyone ‘to do as he likes’ with ’em. I’ll have her patented.”
Leaving the doors open, Andy raced through the house, and in a moment or two had again disappeared within the shop in the grove.