284
Fig, 2—-Frames from a film
Shouing a water drop anda
steel bead under front illumination.
wetting in 7 msec, Show the flattening to be quite pronounced. Contact
was considered to be established when the projected contours touched
in the picture.
The time interval between successive frames was approximately
40 usec. The delay times measured were less than 1 msec, or less
than 26 frames. Very short delay times, of the order of 4 msec, gave
only three or four frames. An error of one frame then causes an error
of 25 to 30% in the delay time. In most determinations of these very