Signalling, and vacuum tubes, 231
by radio, 230

by light and sound waves, 47
history of, 221

in the war, 221 ff.

Smoke, production and use of, 169
Sneezing gas, 153

Soda lime, in gas warfare, 158
Sound-ranging, 41-44
accuracy of, 84
development of, 63 ff.
history of, 66
principles of, 70
results of, 87

Specialization, in research, 405 ff.
Squier, Gen. G. O., relation to In-
formation Service, 35
States Relations, Division of, Na-
tional Research Council,

Tank, leak-proof, for airplanes,

47

Telegraph lines abroad, 225
ground, 243

Telephone lines abroad, 225
Topography, and strategy in the
war, 190

Trade tests, cost of, 382
in army, 381
types of, 383
Trench foot, 295

Trowbridge, A., 63 ff.

Vacuum tubes, and signalling, 231
Vaughan, V. C., 328 ff.

War neuroses, 291

Water, purification of, 281
supply, and geology, 198 ff.
Weather, relations to war, 49 ff.
Welch, W. H., 15

West, C. J., 148 ff.

Wilson, Woodrow, letter, 15
Wounds, splinting of, 318

surgical treatment of, 312 ff.

Yerkes, R. M., 351 ff,