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RULES FOR FINDING THE LATITUDE AND LONGITUDE, AND THE
VARIATION OF THE COMPASS.
With numerous Eramples.
By H. W. JEANS, F.R.A.S.
ROYAL NAVAL COLLEGE, PORTSMOUTH;
Author of a Work on "Plane and Spherical Trigonometry;" "Handbook of the Stars ;"
“Problems in Astronomy, Navigation, &c. with Solutions :" formerly Mathematical
LONGMAN, BROWN, GREEN, AND LONGMANS.
This volume of practical rules and examples will be followed by a theoretical treatise on Navigation and Nautical Astronomy, to be called Part II. It will be the aim of the author, in the forthcoming work, to investigate some of the principal rules and corrections in Nautical Astronomy; but in order to simplify the subject as much as possible, Part II. will be made to consist only of such investigations as require in the student nothing beyond a knowledge of Trigonometry: and only the most simple of these investigations will be selected. Therefore the demonstrations of thé: rules for finding the longitude by occultations, by solar eolipses, transits, &c., as well as the explanation of refraction, of précession, interpolation, &c., and of certain methods for determining the latitude and longitude, which from the peculiar elegance of the artifices used are instructive, and deserve the consideration of the student, —not being of general use, will in Part II. be omitted. They may hereafter be collected and formed into a separate volume, as Part III.
To the present volume is added a rule for finding the time of high-water: it has been now introduced into the book chiefly for students who use Inman’s Tables only.
No rule is given in this volume for finding the latitude by pole-star; the one in the Nautical Almanac, a work which every naval student is supposed to possess, being deemed suf