560 
Notices of Books. 
[October, 
creditable to us that work done in pras-historical times of 
Ceylonese engineers should be better than some completed in 
England in the nineteenth century ? 
BuL Mr. Jackson goes on to say “ At home the catchment 
areas of our rivers, in fadt the country generally, is in a polluted 
state, the drainage both from farm lands and townships being 
still either badly regulated or under no general control. In 
spite of the increasing exceptions the water supply of most of 
our towns is so contaminated as to conduce, among other evils, 
to a fearful amount of intemperance, and the sewage, the natural 
regenerator of soils and crops, is generally allowed to mingle 
with noxious refuse, or to be so ill-regulated as regards dilution 
and application to land, that it not only ceases to be useful, but 
becomes a source of perpetual pollution.” Here, we fear, our 
author is losing his way. We are not aware that intemperance 
is less rampant in Liverpool, Manchester, Glasgow, Leeds, 
Halifax, Huddersfield, Sheffield, and other towns supplied with 
uncontaminated waters from the mountains, than in such as 
draw their water from questionable sources. The selection of 
water and the disposal of sewage are, in our humble opinion, 
chemical not hydraulic questions. Further, defective as maybe 
our water supply and our systems of drainage, we have still the 
satisfaction of knowing that in such points we are certainly not in 
arrear of our continental neighbours. The sanitary shortcomings 
to which we must plead guilty are due more to an over-tender 
regard for “ vested interests ” than to defective knowledge. 
The text of the work before us is devoted to the flow of water 
in open channels generally, and secondly to the flow in open 
channels in earth. Then follow tables of the coefficients of 
mean velocity of discharge, of discharges and mean velocities 
per second, and a supplementary table of percentages for certain 
seconds. The work is a most valuable addition to English 
engineering literature, and we can only regret that it did not 
appear at an earlier date. 
A Treatise on the Trisection of an Angle of Thirty Degrees and 
of any other Plane Angle. By Bernard Tindal Bosanquet. 
London : Effingham Wilson. 
The author of this little pamphlet tells us that “ with regard to 
his theory for the trisedtion of an angle of thirty degrees, he 
feels bound to admit that he has grave doubts as to its truth, 
having failed altogether in finding a geometrical solution.” A 
fair examination of the question would be impossible without 
the aid of the author’s diagrams. 
