18 Lifeand Character of Nathaniel Bowditch. 
ticians have since that-epoch, succeeded in reducing to this great | 
law of nature all the known phenomena of the system of the : 
world, and have thus given to the theories of the heavenly bod-_ 
ies and to astronomical tables, an unexpected degree of precision. — 
My object is to present a connected view of these theories, which — 
are now scattered in a great number of works. The whole of the — 
results of gravitation, upon the equilibrium and motions of the 
fluid and solid bodies, which compose the solar system, and the — 
similar serra existing in the immensity of space, constitute the — 
felestial Mechanics, or the application of the. principles — 
a s to the motions and figures of the heavenly bodies. — 
rca ceod: in the most general manner, is a great prob- | 
lem of mechanics, in which the elements of the motions are the 
arbitrary constant quantities. The solution of this problem. de- — 
at the same time, upon the accuracy of the observations, 
and upon the perfection of the analysis. It is very important to 
_ reject every empirical process, and to complete the analysis, s0 
that it shall not be necessary to derive from observations any but — 
indispensable data. The intention of this work is to obtain; a8 
much as may be in my power, this interesting result.” a2 
» It isa work of great.genius and immense depth, and exceed- 
ingly difficult to be comprehended. | This arises not merely from 
the intrinsic difficulty of the subject, and the medium of proof _ 
being the higher branches of the mathematies,—but 
chiefly from the circumstance that the author, taking it for granted _ 
that the subject would be.as plain and easy to others as to himself, — 
very often omits the intermediate steps and connecting links im~ 
his demonstrations. He jumps over the interval, and grasps the 
conclusion’as by intuition. Dr. Bowditch-used to say, “I never 
eome across one of La Place’s ‘ Thus it plainly appears,’ without — 
feeling sure that I have got hours of hard study before me io fill 
up the chasm, and find out and show how it plainly appears.” | 
Dr. Bowditch says, in his Introduction to the first volume, “ The 4 
object of the author, in composing this work, as stated by him in ‘ 
his Preface, was to reduce all the known phenomena of the sy _ 
tem of the world to the law of gravity, by strict mathematical — 
principles; and to complete the investigations of the motions of 
the planets, satellites, and comets, begun by Newton in his Pris — 
cipia.. - This he has Ne PS in a manner deserving the | ; 
highest praise, for its symmetry and completeness; but from the : 
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