1877J 
Notices of Books. 
419 
party.” But we cannot help remarking that it is in districts 
having a porous subsoil where polluted waters, and other evils 
arising from sanitary negleCt, are most rampant. A stiff corn- 
pad clay opposes an impassable barrier to the diffusion of cess- 
pool and churchyard drainage. But over chalk and gravel, the 
cesspool and the well, though separated by an interval of perhaps 
a dozen yards, are practically identical. In a small town in 
Kent we even found that the sewage, after removal of the solids 
by means of subsidence-pits, was allowed to soak down and dis- 
appear in the permeable subsoil, which must thus become irre- 
deemably saturated with putrescent matter, and must constantly 
give off noxious gases and vapours. 
As regards the antiquity of the human species, the author 
admits that it appeared on the earth’s stage unquestionably at a 
date very much earlier than our forefathers imagined. With 
Mr. Boyd Dawkins, he holds that man was co-existent, in this 
country and in Western Europe, with the lion, the hairy ele- 
phant, and the woolly rhinoceros, and that if his existence can 
be traced back to or even beyond the Glacial epoch, extending 
from 240,000 down to 80,000 years ago, a still higher antiquity 
must be assigned him. 
The work is admirably illustrated, and is furnished with a good 
geological map of England and Wales, with a glossary of tech- 
nical terms, a synopsis of the animal kingdom, a list of the prin- 
cipal works consulted, and a bibliography of the geology of the 
English counties. 
We consider that Mr. Woodward’s work merits almost unqua- 
lifted commendation. 
The Whitworth Measuring-Machine, including Descriptions of 
the Surface-Plates, Gauges, and other Measuring-Instru- 
ments, made by Sir Joseph Whitworth. By T. M. Goodeve, 
M.A., and C. P. B. Shelley, C.E. London : Longmans and 
Co. 1877. 
We all know how very superior English machinery is to that which 
is manufactured by many other countries, but we do not always 
recognise the great share which Sipjoseph Whitworth has had 
in perfecting the machinery whereby our most accurate work is 
done. The authors of the work before us state at the outset 
that “ the two principal surfaces of essential importance in the 
workshop may be distinguished as a ‘ true plane ’ and a ‘ true 
cylinder.’ ” The nearest approach to the former is a surface of 
clean mercury at rest. Sir Joseph Whitworth has devoted much 
time and thought to the production of perfectly plane surfaces 
and accurate methods of minute measurement, and his instru- 
