CRYSTAL PALACE EXPERIMENTS. Having fully satisfied myself that aeroplanes flying around a circle 200 feet in circumference had their lifting effect reduced to no insignificant degree by constantly engaging air which had already had imparted to it a downward movement by a previous revolution, I determined to make some experiments where this trouble could not occur, but the opportunity did not present itself until after the large roundabout, erroneously described as “a captive flying machine,” was put up at the Crystal Palace. This presented a fine opportunity for making experiments at an extremely high velocity around a very large circle. I will only refer to a few of these experiments. To a prolongation of one of the long arms, I attached a thin steel wire rope about 60 feet above the platform; I then attached to this wire rope the little device shown (Fig. 39), in which _a_, is an aeroplane, 5 feet long and 1 foot wide, placed at an inclination of 1 in 20. Great care was used in preparing this aeroplane to see that it was free from blemish, smooth, and without any irregularities. Both edges were sharp and the curvature was about one-eighth of an inch on the underneath side. It was made relatively thick in the middle where it was attached to the bar _c_, and thinner at the ends. _b_, shows a lump of lead just heavy enough to balance the bar _c_, and the tail; _d_, was a light but strong wooden frame, all the edges being thin and sharp, and covered with a special silk that Mr. Cody had found to be best for such purposes. The wire rope _e_, was attached to the long arm which I referred to. The great length of the bar _c_, and the accuracy with which the whole was made and balanced caused the aeroplane to travel straight through the air adjusting itself to all the shifting currents. Upon starting the machine on a very calm day, this apparatus mounted as high as the point of support, sometimes going 10 or more feet higher and sometimes 8 or 10 feet lower. However, as a rule, it carried its own weight at a velocity of 80 miles an hour around a circle 1,000 feet in circumference. Under these conditions, of course, there could be no downward motion of the air as all the air affected would be removed long before it could be struck the second time by the aeroplane. I had no means of ascertaining exactly how much this plane did actually lift, because the air was always moving to some extent, and it was not an easy matter to ascertain whether it was above or below the point of support. I am sure, however, that it was as much as 36 lbs., or rather more than 7 lbs. to the square foot, and this is just what it should have lifted, providing that we consider the results obtained by smaller planes placed in an air blast of 40 miles an hour and at the same angle. When these experiments were finished, I made a very small apparatus having only about 25 square feet of lifting surface, and this carried the weight of a man, in fact several gentlemen