1878.] 
Notices of Books. 
113 
it has, in each succeeding edition, been enlarged and rendered 
more complete. The present additions include sixty-two new 
illustrations, and about sixty pages of new matter. It presents 
in all respects remarkable completeness ; there are numerous 
tables, and four coloured plates, including two which represent 
respectively the isogonic and isoclinic lines for the year i860. 
Few changes have been made in the earlier parts of the book. In 
“ Sound,” however, we find several additions notably relating to 
the synthesis of sounds, Kundt’s determination of the velocity of 
sounds, and Koenig's manometric flames. In Heat, the subject of 
Radiant Heat is treated more fully, an account of Crookes's 
Radiometer and the theory of its action, Bunsen's Ice-Calorimeter, 
and the sources of cold. An interesting description of Horn’s 
method of determining the mechanical equivalent of heat will be 
found on p. 410. 
In Light, the construction and use of Hedley’s Reflecting Sex- 
tant is given, and the measurement of small angles by reflection 
from a mirror. The Spectroscope is treated much more fully 
than before, also the whole subject of the eye. The chapters on 
Magnetism are enlarged and much improved since the earlier 
editions, and the plates showing isogonic and isoclinic lines are 
beautifully clear and intelligible. In Electricity, the applications 
of the discharge to the firing of mines has been introduced ; also 
a woodcut, and brief account of Leclanche’s battery (unaccom- 
panied, however, by the equation which expresses the change 
within the battery). A graphic representation of the heating 
effects in a circuit is given on p. 710, and the mechanical effects 
of the battery on p. 718. The science of Electro-dynamics is 
treated at greater length than before, and several new woodcuts 
have been introduced to illustrate this portion of the subject. 
The sounder telegraph receives no more than a passing notice ; a 
woodcut in the next edition would be acceptable in this connection. 
Becquerel’s electric thermometer is described in detail and figured, 
and the subject of animal electricity receives greater attention 
than hitherto. In the Meteorology and Climatology a description, 
accompanied by a good engraving of Secchi’s Meteorograph, will 
be found ; also Tyndall’s researches on the influence of aqueous 
vapour on the radiation of heat, and on the blue colour of the 
sky. The volume is concluded by 221 well-selected problems and 
examples in various branches of Physics, the answers to which 
are given. 
We congratulate Prof. Atkinson on the completeness and tho- 
roughness of his work in connection with the new edition of 
Prof. Ganot’s “ Physics.” 
VOL, VIII. (N.S.) 
I 
