3?7 
1876.] Notices of Books. 
The following* speculation is at any rate curious : — “ A dimi- 
nution of the weight of the atmosphere may be justly inferred 
from the fa eft that extinct species of animals, as seen in fossil 
remains, appear to have been collectively created on a larger 
scale than the corresponding species at present existing. Heavy 
animals were relatively more numerous, and weight rather than 
agility characterised the figures of all.” Now, that certain ex- 
tinCt animals must have been larger than any now existing is 
admitted ; but we are unable to discover any regular and serial 
decrease from the earliest epochs downwards. “ Under a very 
heavy atmosphere,” says Mr. Cooley, “ the elephant would feel 
relieved of much of its weight, and become a comparatively 
aCtive animal.” Unfortunately the elephant and the rhinoceros, 
clumsy as they look, are decidedly aCtive animals. 
As a theorist we do not think the author happy ; but he has a 
remarkable facility for collecting anomalies and pointing out un- 
solved problems. Hence this work may be pronounced exceed- 
ingly suggestive, and must be recommended to the careful study 
of geologists. 
Practical Plane Geometry. By E. S. Burchett. London and 
Glasgow : W. Collins, Sons, and Co. 
This work is in its objects and nature totally different from 
“ Euclid’s Elements.” It has been compiled, as the author in- 
forms us, “ on account of a strongly-felt want of a more complete 
text-book upon the subject.” Its aim is practical, not theoretical. 
Hence, beyond the introduction, it consists of problems and of 
applied geometry, including such subjects as the repetition of 
geometric figures to fill plane surfaces, the lines of arches, the 
curves of mouldings, Gothic tracery, and the construction of 
scales. An Appendix treats of the elements of orthographical 
projection. 
We consider the work likely to prove of no small value to 
architects, builders, and to designers of ornamental work in 
metals, glass, and other materials. 
Annual Report of the Board of Regents of the Smithsonian 
Institution for the Year 1874. Washington : Government 
Printing Office. 
This yearly issue contains the Report of the Secretary, Prof. 
Henry, including the financial statement ; list of publications 
issued and in the press j account of researches conducted in 
2 m a 
