1

PRINTED BY HILLIARD AND METCALF,
At the University Press.

SOLD BY W. HILLIARD, CAMBRIDGE, AND BY CUMMINGS, HILLIARD, & co.

NO. 134 WASHINGTON STREET, BOSTON.

1825.

DISTRICT OF MASSACHUSETTS, TO WIT.

District Clerk's Office.

BE it remembered that on the twenty-ninth day of September, 1825, in the fiftieth year of the Independence of the United States of America, Cummings, Hilliard & Co. of the said district, have deposited in this office the title of a book, the right whereof they claim as proprietors, in the words following, viz:

"An Elementary Treatise on Mechanics, comprehending the Doctrine of Equilibrium and Motion, as applied to Solids and Fluids, chiefly compiled, and designed for the use of the Students of the University at Cambridge, New England. By John Farrar, Professor of Mathematics and Natural Philosophy."

In conformity to the act of the Congress of the United States, entitled "An act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies, during the times therein mentioned ;" and also to an act, entitled, "An act supplementary to an act, entitled, 'An act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies, during the times therein mentioned,' and extending the benefits thereof to the arts of designing, engraving, and etching, historical and other prints."

JNO. W. DAVIS,

Clerk of the District of Massachusetts.

ADVERTISEMENT.

IN selecting materials for this treatise particular regard has been had to the practical uses of the science; at the same time the theoretical principles are rigorously demonstrated. Where the nature of the subject admitted of it, the geometrical method has been preferred, as being more perspicuous and better adapted to most learners. There are many refinements in the later and more improved treatises not adopted in this, for the reasons above mentioned, and on account of the insufficient provision, as to time and preparatory studies, that is made in most of the seminaries of the United States for a text-book upon such a plan.

The works principally used in preparing this treatise are those of Biot, Bézout, Poisson, Francœur, Gregory, Whewell, and Leslie. In the portions selected it was found necessary to make considerable alterations and additions in order to give a uniform character to the whole. There has often been occasion, moreover, in appropriating the substance of a proposition or course of reasoning, to amplify or condense it, or to vary the phraseology. It became inconvenient, therefore, to distinguish by quotations the respective portions taken from different authors. Bézout has been adopted, in substance, as the basis in what relates to statics, dynamics, and hydrostatics, although the matter is arranged