Alexander G. McAdie
in these currents were made to float, or rest in equilibrium. So he found out a great deal about the way in which [illegible]fall and measured their velocities. The greatest velocity was about 8 meters per second, say 26 feet. The first effect of the current of air on the shape of the drop was to flatten it, then he was able to cause circulations or vortex movements around the drops (I have seen the same thing happen in a drop of dew, which was slowly evaporating. A speck of dust whirlled around and round the equator of the drop. I am working on this now with a microscope and may get some illustrations latin • Lenard found that the fine drops are far in excess of large drops;and they don't change in a regular gradation; but gather in groups. Sometimes the intermediate sizes are missing. Now what happens within the cloud mass. Something akin to the smallest rain drops evidently forms and float with others of their kind. There can be in one cubic inch of cloud mass, a million and more of these little drops, trying to get away; but too light and too small in their own proper selves to have much motion. Physicists think that under certain conditions an electrification of the drop occurs, and by a series of strong attractions and repulsions04734
1910 Mar 19
Original letter dimensions: 25 x 20 cm.
Reel 19, Image 0259
Copyright status unknown