66 Notices respecting New Books. 
wich observatory, showing a remarkable coincidence between 
terrestrial magnetic storms and solar disturbances observable 
as sun-spots. These observations completely confirm my 
brother's views on this subject, and agree also with those I 
ventured to put forward in my original paper. 
X. Notices respecting New Books. 
Sir William Hamilton: the Man and his Philosophy . Two Lectures 
delivered before the Edinburgh Philosophical Institution, .January 
and February, 1883. By John Veitch, LL.D. (W. Blackwood 
and Sons ; 1883 : pp. 68.) 
" T HAVE got but one hour this evening to put before you the 
■*- method and the main results of a great philosophy, the work 
of a man's lifetime." So opens the second lecture, which gives a 
rapid sketch of a philosophy, admittedly put forth to the world 
in fragments ; but " from the stately parts " of which " we can 
imagine the greatness of the whole, had the master's hand given 
them union and cohesion." Lectures written under the con- 
dition indicated above cannot be expected to go deep down into 
the subject ; and all the reader can reasonably look for is a clear 
and accurate presentment of facts. This he will find furnished 
in this interesting sketch. Students who want fuller details will 
find these in the same writer's larger work in Messrs. Blackwood's 
' Philosophical Classics for English Readers.' With one of 
Hamilton's opponents we say, " Long five the memory of William 
Hamilton, good, learned, acute, and disputatious." 
On the Motion of a Projectile in a Resisting Medium, and particularly 
when the Resistance varies as the Cube of the Velocity. By A. G. 
Gbeenhill. (Woolwich ; printed at the Royal Artillery In- 
stitution, 1882 : pp. 32.) 
Mr. Bashforth's " Motion of Projectiles " contains a lengthy set 
of tables from which by laborious processes the path of the 
projectile may be constructed with almost any desired amount of 
accuracy*. Prof. Greenhill comes to the consideration of the 
problem with his almost unequalled mastery of elliptic-function 
methods, and, as a result inter alia, appears to have simplified 
the calculation of some of Mr. Bashforth's tables. At the 
close are appended some practical tables, drawn up by Captain 
P. A. Macmahon, E.A., worked out from values given in Mr. 
Bashforth's "final report on experiments with the Bashforth chrono- 
graph,'' 1880. Though we cannot pronounce upon the technical 
applications of the paper, we have read Prof. Greenhill's elegant 
analysis with interest. 
* Encycl. Met., art. Gunnery. The term laborious does not, of course, 
imply that blame rests upon the writer of this classical treatise : even the 
cubic law, the simplest tc work with, is fraught with difficulty. 
