The immense strides that have recently been made in instantaneous photography, owing chiefly to the advent of the dry-plate process, have caused photography to become useful to almost every branch of science.

To Muybridge and Anschutz we are greatly indebted for the strides made in instantaneous photography. These gentlemen have succeeded in photographing moving objects hitherto considered impossible to be photographed. Galloping horses, swift-flying birds, and even bullets and cannon balls projected from guns have been successfully photographed, showing even the little head of air driven along in front of the bullet.

FIG. 79.

Both Muybridge and Anschutz also succeeded in making series of twenty-four or more photographs of a horse during the time it makes a single leap, and thus illustrated its every movement. The value of these and other possibilities with the camera for artists cannot be overestimated. Its aid to meteorologists in photographing the lightning, to astronomers in stellar, lunar and solar photography, and to all other sciences would require a work as large as this to describe.

By Lt. Joachim Steiner.
FIG. 80.—INSTANTANEOUS STUDIES.

For the making of instantaneous pictures a large number of suitable cameras have been devised. In most of these the lens is a very rapid one, and in some cases so arranged that all objects beyond a certain distance are in focus. With an instantaneous camera a secondary image is necessary, so that the right second can be judged for making the exposure. This is usually produced by a finder. In making instantaneous exposures the following tables may be useful:

Approximate distance

A man walking 3 miles per hour moves4-1/2Feet per second
A man walking 4 miles per hour moves6Feet per second
A vessel traveling at 9 knots per hour moves15Feet per second
A vessel traveling at 12 knots per hour moves19Feet per second
A vessel traveling at 17 knots per hour moves28Feet per second
A torpedo boat traveling at 20 knots per hour moves35Feet per second
A trotting horse36Feet per second
A galloping horse (1,000 yards per minute)50Feet per second
An express train traveling at 38 miles an hour59Feet per second
Flight of a pigeon or falcon 61Feet per second
Waves during a storm65Feet per second
Express train (60 miles an hour)88Feet per second
Flight of the swiftest birds294Feet per second
A cannon ball 1,625Feet per second
An object moving—
1 mile per hour1-1/2Feet per second
2 miles per hour3Feet per second
5 miles per hour7-1/2Feet per second
6 miles per hour9Feet per second
7 miles per hour10-1/2Feet per second
8 miles per hour12Feet per second
9 miles per hour13Feet per second
10 miles per hour14-1/2Feet per second
11 miles per hour15Feet per second
12 miles per hour17-1/2Feet per second
15 miles per hour22Feet per second
20 miles per hour29Feet per second
25 miles per hour37Feet per second
30 miles per hour44Feet per second
35 miles per hour51Feet per second
40 miles per hour59Feet per second
45 miles per hour66Feet per second
50 miles per hour73Feet per second
55 miles per hour80Feet per second
60 miles per hour88Feet per second
75 miles per hour110Feet per second
100 miles per hour147Feet per second
125 miles per hour183Feet per second
150 miles per hour220Feet per second
200 miles per hour257Feet per second