270 
Dr. U. Nakaya—ULast year we made a movie 
film which shows the mechanism of a small drop- 
let captured on the surface of ice; these ice sam- 
ples are polished and are exposed to the air for 
some time. We place a very small water droplet 
(one or two microns) on the surface. This drop- 
let does not freeze to the surface of the ice but 
it rolls over the surface getting smaller and 
smaller and, finally, it vanishes. That means this 
DISCUSSION 
droplet as a whole freezes onto the surface, but 
does not give a rimed crystal. It spreads out over 
the surface evaporating very quickly within 0.01 
and 0.1 second. 
Dr. Hitschfeld—Obviously, this has not been 
taken into account, but I doubt that it would 
change Dr. Douglas’ results very greatly if it 
had. 
