682 
NATURE 
[FEBRUARY 19, 1914 
POPULAR AND SPECIAL PHYSICS. 
(1) Wireless Telegraphy and Telephony without 
Wires. By C. R. Gibson. Pp. 156. (London: 
Seeley, Service and Co., Ltd., 1914.) Price 2s. 
net. 
(2) A Text-book of Physics. By Dr. R. S. 
Willows. Pp. viii+471. (London: Edward 
Arnold, n.d.) Price 7s. 6d. net. 
(3) Medizinische Physik. By Prof. Otto Fischer. 
Pp.. xx+1120. (Leipzig: S. Hirzel, 1913.) 
Price 36 marks. 
(4) Principles of Thermodynamics. By Prof. 
G. A. Goodenough. Second edition, revised. 
Pp. xiv+327. (London: Constable and Co., 
Ltd., 1913.) Price 14s. net. 
(r) R. GIBSON’S book is a brightly written 
account of the development of wireless 
telegraphy, with just sufficient broadly popular 
explanations to give the ordinary reader the 
impression that he is understanding the nature of 
electricity and of electric waves. The historical 
sketch in chap. iv., in which the early suggestions 
and experiments of Steinheil, Morse (1844), 
Lindsay (1854), Trowbridge, and Preece (1882) 
find their due place, is very good reading, and 
the account of Lodge’s syntonic jars and the im- 
provements effected by Jackson, Righi, and Popoff 
brings out many points on which the ordinary 
man’s memory has become somewhat hazy. 
Then comes Marconi’s “antenna” and earthed 
apparatus, which increased the effectiveness of 
radiotelegraphy a hundredfold, and led to its most 
striking triumphs. From that time forward 
“wireless” and “Marconi” become almost syn- 
Onymous among English speakers, but the 
German combination of the Braun-Siemens and 
Slaby-Arcs systems now known as the “Tele- 
funken” system is allowed some space, and the 
American systems of de Forest and Fessenden, 
as also the Danish Poulsen system, are briefly 
described. A chapter on “telephoning without 
wires,” a chronological table, and a short glossary 
of terms conclude a pleasing and eminently read- 
able volume. 
(2) Dr. Willows’s ‘“Text-book of Physics” 
treats the elementary phenomena rather more fully 
than do other works of a similar kind. One 
would suppose it to be intended mainly for self- 
tuition, to judge by the numerous examples (with 
answers) and the rather detailed style. The 
ground covered is the same as that already sur- 
veyed in countless physical works, and there is not 
much that is new, either in subject-matter or 
method of treatment, though one is pleased to see 
Callendar and Barnes’s “J” apparatus, the hot- 
wire ammeter, and the moving-coil galvanometer 
NO. 2312, VOL. 92| 
duly explained. The illustrations are good, 
except Fig. 134 (erecting prism), which is in- 
correctly drawn. There ate some minor short- 
comings, such as the quite incredible explanation — 
of osmotic pressure on p. 15, but on the whole it 
is a thoroughly useful and creditable work, which 
will no doubt be widely appreciated. ; 
(3) A special work on ‘‘Medical Physics” is — 
necessarily of a somewhat limited scope, but eclec- 
ticism has been carried almost to an extreme in 
Prof. Otto Fischer’s substantial volume. It re- 
solves itself into a collection of treatises on three 
or four chosen subjects. The first and most volu- 
minous of these is the work on the kinematics 
and kinetics of linkages, with special reference 
to joints. It gives graphic methods for the kine- 
matic analysis of the empirically determined 
motion of a point, and methods of compound- 
ing translational and _ rotational velocities, 
demonstrates the equivalence of the most general 
finite displacement of a body in space with a screw 
motion, and reduces the kinetics of manifold link- 
ages to the kinetics of single, rigid bodies. Many 
examples are given, and the mathematical treat- 
ment is reduced to its simplest terms. One cannot 
help wishing that this portion of the book had 
been published separately, as it is self-contained, — 
and the whole work, weighing more than 4 lb., 
makes an unwieldy handbook. The remainder of 
the volume gives certain chapters of acoustics 
and optics. The former comprise stationary and 
progressive waves, sound analysis, the physics of 
the ear, and the voice mechanism. The optical 
portion is a treatise on geometrical optics, the 
microscope, and the polarimeter. Only twelve — 
pages are devoted to the human eye. If it were 
not for the many numerical problems and examples — 
which form the most valuable feature of this 
work, one would scarcely see much prospect of 
it successfully competing with its many rivals. — 
In a work on medical physics, one would have 
expected something on the motion of liquids in 
, elastic and capillary tubes, on osmose and dialysis, 
on thermometry and hygrometry, on spectroscopy, 
on string galvanometers, nerve currents, and 
cardiograms. All this is conspicuous by its 
absence. It is a pity to see the utility of this 
otherwise admirable work curtailed by such faults 
of publication and presentation. 
(4) Prof. Goodenough’s ‘Thermodynamics ” 
aims primarily at laying an adequate foundation 
for the advanced study of heat engines. The 
treatment of the fundamental laws is that of 
Bryan, which identifies the “second law” with 
the law of degradation of energy, and defines 
entropy in terms of unavailable energy. Chapters 
