PRINTED AND PUBLISHED BY HEZEKIAH HOWE.
Sold also by COLLINS & HANNAY, New York; and
JOHN GRIGG, Philadelphia.

1831.

L. S.

DISTRICT OF CONNECTICUT, ss.

BE IT REMEMBERED; That on the third day of January, in the fifty fifth year of the Independence of the United States of America, JEREMIAH DAY, of the said district, hath deposited in this Office, the title of a book, the right whereof he claims as Author, in the words following, to wit:

"The Mathematical Principles of Navigation and Surveying, with the Mensuration of Heights and Distances. Being the fourth part of a Course of Mathematics, adapted to the method of instruction in the American Colleges. By Jeremiah Day, D. D. LL. D. President of Yale College."

In conformity to the Act of 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 time therein mentioned."-And also to the act, entitled, An act supplementary to an act, entitled An act for the encouragement of learning, by securing 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."

CHARLES A. INGERSOLL, Clerk of the District of Connecticut.

A true copy of record, examined and sealed by me,

CHARLES A. INGERSOLL, Clerk of the District of Connecticut.

As the following treatise has been prepared for the use of a class in College, it does not contain all the details which would be requisite for a practical navigator or surveyor. The object of a scientific education is rather to teach principles, than the minute rules which are called for in professional practice. The principles should indeed be accompanied with such illustrations and examples as will render it easy for the student to make the applications for himself, whenever occasion shall require. But a collection of rules merely, would be learned, only to be forgotten, except by a few who might have use for them in the course of their business. There are many things belonging to the art of navigation, which are not comprehended in the mathematical part of the subject. Seamen will of course make use of the valuable system of Mackay, or the still more complete work of Bowditch.

The student is supposed to be familiar with the principles of Geometry and Trigonometry, before he enters upon the present number, which contains little more than the application of those principles to some of the most simple problems in heights and distances, navigation, and surveying.