Review of O. Gregory's Treatise on Me-hanics. 85 
more force, and elegance by Maclaurin. The whole of 
this long, and elaborate investigation is taken from Don 
Juan’s examen maritimo. f.! 
The 6th and last chapter on Dynamics is that, which 
treats of the maximum effects of machines. As this part of 
the work censists chiefly of problems selected from differ- 
ent authors we pass it over in silence. 
The next great division of our author’s work, which he 
has brought under the denomination of Mechanics, is what is 
usually denominated in English Hydrostatics, and Hydrau- 
lies, but by our author, and the French writers, the latter is 
termea Hydrodynamics. Considering fluids as subject to 
the laws of mechanical philosophy, the latter nomenciature 
is perfectly proper, and analogous to that of the first part of 
the work. . 
We might go into details of this part of our author’s book, 
as we have into some of the first, but it would not be con- 
sistent w:th our prescribed limits. The same character per- 
vades the whole, excepting, that the latter subjects are more 
incumbered with experiments, often of a frivolous import, 
than the former. 
In addition to what we have before remarked, another, 
and very material fault of this book is the spirit of generali- 
Ps tule ais 
it Cl 
pervade it. In philosophy,according to Baconian principles, a 
general principle ought never to be assumed, unless so ma- 
ny particulars unite in one principle as to render it wholly 
indisputable. But admitting the particulars are sufficiently 
numerous, and well selected, so as to bear the test of in- 
stantia crucis, or experimentum crucis ; yet ge princi- 
ples and formule so useful to the mathematician, who must 
be supposed to be well versed in particulars, are not those 
by which a subject can be best illustrated, and rendered 
comprehensible to a learner. ‘This assumption of general 
en in the exact sciences, before the mind has been 
amiliarized with the reasonings and results of particular ca- 
Ses, borders very near on Cartesian Hypotheses, or at least 
is no great discrepancy in the two methods. We 
therefore agree with Dr. Watts, who, in his improvement 
of the mind recommends, that a student of the mathematics, 
proceed from practical or particular cases coming under | 
notice and observation, to those which require more general 
