Trying to read Glenn Curtiss's mind I would guess that he looked at the ailerons as small wings and therefore he could get force to control the roll of the airplane. He could get a good idea of the force available based on the limited data he had on wings. Half way between was probably determined by the thought to get the surface away from the other wings. The concept of a separate movable attached surface as we have with modern airplanes was still in the process of invention.

I don't know about the Kitfox. I do remember wondering about it the first time I saw it. Certainly the ailerons will work there but looking at airplanes that have to work for a living gives a big thumbs down for that design. Too much drag when it isn't being deflected.

They do make a great sound going through branches though don't they? It is a tribute to my concrete building style that not much got hurt the two times I have managed to do it. It is a good thing though as my tree climbing days are quite over and even before then I am a severe heightaphobic. If I can reach it with a stick I just beat it until the parts are small enough to come down.

I fly little yard and park fliers in the back of my house. There is a 1/2 square of open area with a ravine that makes a great sledding hill for the neighborhood kids but it is surrounded on three sides by old trees 50 ft high or so. I am trying to train the squirrels as retreivers but all they do is eat the seeds I put out for the birds and bicker. I suppose I'll have to go to the local Rent-a-Monkey when the time comes.