, magnetic, 209-11

Velocity of light, 148
of electric waves, 182
of heat waves, 148
of falling bodies, 21
of wave motion, 76

Velocity, angular, 250

Venus, 33, 68, 79
a magnet, 197
mass of, 235
rotation of, 219
orbital velocity of, 251
periodic time of, 251

Vibration, atomic, 75

Vibrations, transverse, 130
longitudinal, 130
of sound, 123

Vibratory motion, 91

Vogel, Prof., 308, 312

Vogt, Prof., 332

Volume of sun, 27

Von Asten, 234, 296

Vortex theory, 92, 337
motion, 221-4
atom, 93, 126, 337
rings, 125, 337

Vortices, molecular, 103

Water waves, 124
currents, power of, 95
composition of, 141
power, 88

Wave front, 128
motion, 124, 160

Wave lengths, 120
envelope, 112

Waves, chemical, 141
sound, 104, 120, 124
light, 126
heat, 141
electric, 159
spherical, 112
electro-magnetic, 165

Weight, 29, 69, 84
variation of, 29
pound, 30

Whewell, 3, 221

Winds, 81, 90
energy of, 90
trade, 225

Work, 96
and energy, 84
from heat, 116

Young, Thomas, 54, 64, 67, 123
on aether, 58
fourth hypothesis, 70
Prof., of America, on electric space, 166

Zinc, 88

Zodiacal light, 277-9

_Richard Clay & Sous, Limited, London & Bungay._

Some New Publications

OF

Messrs. Chapman & Hall, Ltd.

1903-4

* * * * *

MR. H. G. WELLS'S NEW WORK.

MANKIND IN THE MAKING. By H. G. WELLS, author of "Anticipations," etc.
Crown 8vo, _7s. 6d._

In this new and important work Mr. Wells attempts to deal with social
and political questions in a new way and from a new starting-point,
viewing the whole social and political world as aspects of one universal
evolving scheme, and placing all social and political activities in a
defined relation to that; and it is to this general method and trend
that the attention of the reader is especially directed.

DR. ALFRED RUSSEL WALLACE'S NEW BOOK.

MAN'S PLACE IN THE UNIVERSE. A study of the results of scientific
research in relation to the unity or plurality of worlds. By ALFRED
RUSSEL WALLACE, LL.D., D.C.I., F.R.S., author of "Natural Selection,"
"Darwinism," etc., etc. With Diagrams. Demy 8vo, _12s. 6d. net_.

This volume is an amplification and extension of the muc