134 
Notices of Boohs. 
[January, 
Elements of Physical Manipulation. By Edward C. Pickering, 
Thayer Professor of Physics in the Massachusetts Institute 
of Technology. Part II. Macmillan. 1876. 
The first portion of this work was published three years ago, 
and comprised the Mechanics of Solids, Liquids, and Gases, 
Sound, and Light. The present volume completes the cycle of such 
work as may be performed in a physical laboratory, and includes 
Electricity, Heat, Mechanical Engineering, Meteorology, Prac- 
tical Astronomy, Lantern Projections, and an Appendix contain- 
ing various Tables. 
A fourth of the work is given to EleCtricity. Commencing 
with a short description of batteries, keys, plugs, connections, 
switches, and commutators, he passes to the method of using 
them, and thence to the telegraph. The Morse telegraph only 
is described, and the account is somewhat meagre, but the 
testing of telegraphs and of submarine cables is discussed 
further on. Altogether, that part of the work devoted to 
eleCtrical manipulation is somewhat disappointing, and it is 
quite insufficient for the present wants of students. 
The section on Heat commences with an account of testing 
thermometers, and of the determination of the expansion of 
solids, liquids, and gases. The experiment (No. 127, p. 82) for 
determining the change of volume by fusion, as there described, 
is quite impracticable and impossible, and no student could 
obtain a satisfactory result by the use of it. Neither does the 
small accompanying woodcut make the matter much clearer. 
Under the head of pyrometers we find (in a space of two pages) 
an account of Wedgwood’s pyrometer, the use of which has 
been long abandoned, also of the thermopile pyrometer, the 
pyrometer depending on the specific heat of platinum, and 
Siemens’s pyrometer; but the accounts are so slight as to be 
useless without a considerable amount of collateral information 
obtained from some other source. The appliance recently 
described for illustrating the mechanical equivalent of heat as a 
leCture experiment is figured and described, but the name of the 
originator of the apparatus is not once mentioned. 
The seCtion on mechanical engineering is a novel feature in a 
work on physical manipulation. The author accounts for it as 
follows : — “ Physical problems which are to be solved on a large 
scale require a thorough knowledge of mechanical engineering. 
To this class belong also those which have the greatest pecuniary 
value. The methods of conducting such experiments also are 
often so faulty that a brief description of how they should be per- 
formed will not seem out of place.” The proper care of a boiler 
and of an engine is first discussed. The author points out that the 
loss of heat by condensation and radiation when steam passes 
through a great length of piping is much more considerable than 
is often supposed. By covering the pipes with canvass, or felt, 
