TABLE OF CONTENTS The soaring speeds determined in these two series of experiments are plotted in Figs. 8 and 9, in which the absciss are angles of inclination of the planes to the horizon, and the ordinates are the soaring speeds which correspond to them. Figure 8 contains the observations made with the planes that weigh 250 and 1,000 grammes to the square foot, and Fig. 9 those made with the planes that weigh 500 grammes to the square foot (5,382 grammes to the square meter). The experiments with the first two of these classes of planes, plotted in Fig. 8, were not repeated, and consequently the curves do not possess so high a quantitative value as obtains in the case of most of the planes weighing 600 grammes to the square foot, but they serve to present several fundamental relations:
First, they show quantitatively, when taken together with the curves of Fig. 9, the increase of velocity necessary to sustain the heavier planes (per unit area) over that which will sustain the lighter ones, at the same angle of inclination.
Second, the curves both of the 250 and the 1,000 gramme planes show the difference due to shape and aspect, the soaring speeds, for small angles of inclination, being much less for those planes whose extension from front to back is small, than for those in which this dimension is large, so that, in general, the planes having this dimension smaller, for small angles of inclination,...
