TREATISE ON NAVIGATION

AND

NAUTICAL ASTRONOMY,

ADAPTED TO PRACTICE, AND TO THE PURPOSES OF
ELEMENTARY INSTRUCTION;

WITH

AN EXTENSIVE SERIES OF EXAMPLES FOR EXERCISE, AND ALL THE TABLES
REQUISITE FOR NAUTICAL COMPUTATIONS.

FOURTH EDITION,

WITH RULES AND EXAMPLES ADAPTED TO THE NAUTICAL ALMANAC
IN ITS NEW AND IMPROVED FORM.

BY EDWARD RIDDLE, F.R.A.S.,

MASTER OF THE NAUTICAL SCHOOL, ROYAL HOSPITAL, GREENWICH.

LONDON:

ROBERT BALDWIN, 47, PATERNOSTER-ROW.

MDCCCXLII.

ΤΟ

THE RIGHT HONOURABLE

THOMAS EARL OF HADDINGTON;

ADMIRAL

THE RIGHT HONOURABLE SIR GEORGE COCKBURN, G.C.B.;

VICE-ADMIRAL SIR WILLIAM HALL GAGE, G.C.H.;

REAR-ADMIRAL SIR GEORGE FRANCIS SEYMOUR, Kt., G.C.H.;

CAPTAIN HON. WILLIAM GORDON;

AND

THE RIGHT HONOURABLE HENRY THOMAS LOWRY CORRY;

THE LORDS COMMISSIONERS FOR EXECUTING THE OFFICE OF LORD HIGH ADMIRAL OF THE UNITED KINGDOM OF GREAT BRITAIN AND IRELAND,

THIS

NEW AND IMPROVED EDITION OF A WORK

DESIGNED TO IMPART TO THE

PROFESSIONAL EDUCATION OF BRITISH SEAMEN A MORE SCIENTIFIC
CHARACTER THAN IT HAS HITHERTO GENERALLY ATTAINED,

IS,

WITH THEIR LORDSHIPS' PERMISSION,

RESPECTFULLY INSCRIBED, BY

THE AUTHOR,