78 Review of O. Gregory’s Treatise on Mechanics. 
and strictly fluxional, cannot indeed be reduced to the 
Euclidean method of demonstration so much celebrated ; 
but a great number of them may be illustrated, if not de- 
monstrated, on principles depending on the common ge- 
ometry, or those which are obvious, and universally re- . 
ceived as incontrovertible. This is abundantly manifested 
by what has been done by Simpson, and the more elegant 
and profound Maclaurin. These remarks, though applica- 
ble to the writings of some of the most celebrated modern 
mathematicians, are more particularly so to those books 
written. apparently more for the purpose of making a pa- 
of science, than affording instruction to readers of the 
common class. The spirit of ancient times, when difficult 
arts were intentionally enveloped in mystery, has not 
wholly evaporated at the present time. Even mathematt- 
cians appear desirous of gaining celebrity and admiration 
-by unnecessary and most elaborate extensions of the most 
recondite, and to any besides themselves, the most myste- 
rious and unintelligible part of their noble and favourite 
to extend the knowledge of it, and of that branch of science 
of which it treats, hitherto little cultivated in theory, in 
this country, by an impartial analysis of that, which we 
consider, on the whole, as the best, and by far the most 
rofound treatise on the subject, which has appeared in 
the English language. 
It is not within the compass of our design, to select many 
portions of this book which are most deserving of praise, 
or liable to censure. Works of science should he estima- 
ted by their effect on their ultimate objects, truth and 
practical utility. We shall, therefore, in our remarks, be 
confined chiefly to those parts of this production, which in- 
volve principles, as being by far the most important to the 
scientific reader. 
_ In Art. 71, we have this proposition, “ If two parallel 
forces act perpendicularly on a ee, line in the > 2 di- 
rection, their resultant is parallel to them, acts in the same 
lirection, is equal to their sum, and divides the line of ap- 
plication into two parts, which are reciprocally proportion- 
