THE DIFFERENT KINDS OF SAILING,

AND NECESSARY CORRECTIONS FOR LEE-WAY, VARIATION, &c.

EXEMPLIFIED

IN A JOURNAL AT SEA:

TOGETHER WITH

panies for War, defcribing the Exercife of the great Guns, and the requifite Manœuvres for attacking or defending a Ship:

All neceffary Inftructions for determining The Manner of exercising Ship's Comthe Latitude by DOUBLE ALTITUDES of the Sun, by the Moon, the Planets, and fixed Stars; and for afcertaining the LONGITUDE by the LUNAK OBSERVATIONS, and other Methods. The Manner of finding and knowing the Planets and fixed Stars, by Calculation and Planispheres.

The Art of Surveying Sea-Coafts and
Harbours.

An Abstract of Practical Seamanship,
fhewing the Method of Working a
Ship in all difficult Cafes at Sea.

The Method of recovering Ships in different Situations of Diftrefs, and keeping them from a Lee-fhore, with the beft Means of faving Perfons from Wrecks; and the Procefs of recovering drowned People, recommended by the Royal Humane Society; with a Variety of Articles not to be found in any other Book of this Kind.

THE WHOLE ILLUSTRATED WITH ENGRAVINGS, And rendered eafy to the most common Capacity.

The TABLES in this Book have been examined by three Perfons; and, it is trufted, are the most correct extant.

So that this Book will be found fully fufficient either for the Teacher or for Practice at Sea.

HYDROGRAPHER, SEA-BOOK, INSTRUMENT, AND CHART-SELLER.

London:

PRINTED FOR J. JOHNSON; W. J. AND J. RICHARDSON; F. AND C. RIVINGTON; G. WILKIE AND J. ROBINSON; J. WALKER; G. ROBINSON; SCATCHERD AND LETTERMAN; C. LAW; DARTON AND co.;

CROSBY AND CO.; LACKINGTON, ALLEN, AND CO.;

LONGMAN, HURST, REES AND ORME; J. AND J. ·
HARDY; R. PHILLIPS; AND R. SCHOLEY.

Printed by J. CROWDER, Warwick-square.

Right Hon: GEORGE JOHN EARL SPENCER,

VISCOUNT ALTHORP,

AND

MASTER OF THE TRINITY-HOUSE.

THIS

NEW AND MUCH-IMPROVED EDITION

OF

THE PRACTICAL NAVIGATOR,

IS RESPECTFULLY DEDICATED,

By his Lordship's much-obliged,

And very humble Servant,

JOHN HAMILTON MOORE.

MAY 1ft, 1807.

74

An Account of the Arrangement and Improvements in this Edition.

THE HE favourable reception which this Work has met with, embal dens me to prefent before the Public the prefent Edition; in which, I truft, I have introduced fuch improvements as will continue to me the favour which I have fo long had the happiness to enjoy. In my former Editions I had digefted the feveral Articles into a natural and fimple order, and endeavoured to show how every thing might be deduced from the firft and moft fimple principles of the Mathematics; in which, I truft, I had fo far fucceeded, as to render it easy to the most common capacity. How beneficial a work of this kind muft be to Learners cannot be doubted, when we reflect, that by being thus acquainted with the true principles of things, they will retain better what they have learned, and be enabled to make much greater progrefs in the art, than could otherwife poffibly take place. Indeed, upon a careful perufal of the Work, I found the plan I had purfued, fo far as regards the parts of Navigation ufually taught and practifed at fea, could not be amended in the bulk, though fome improvements might be made in particular parts. It particularly occurred to me, that I had invariably found young Gentlemen, who attended me for a private examination, previous to their paffing a public one, deficient in working an obfervation in all the variety of fituations which may take place. In this Work I have accordingly elucidated this important article, by giving a Rule for every different fituation, in which the obferver can poffibly find himself in refpect of the Sun; illuftrating each with a projection on the Plane of the Meridian.

There is introduced into this Edition, a Table for the near calculating the Time of High Water, with the affiftance of the Nautical Almanack.

I pass over many others of fmaller note in the first part of the Book, fuch as partial Amendments of the Style, &c. in hafte to give an ac Count of the Arrangements and Additions in the latter part of this WORK, which is for the most part New.

Previous to the year 1767, when the first NAUTICAL ALMANACK was published, the practice of finding the Longitude at Sea was univer. Sally by account. The mode of afcertaining it by taking the Moon's distance from the Sun, or a fixed Star, commonly called the LUNAR OBSERVATIONS, was attended with difficulties infurmountable to moft Mariners. By the unremitting affiduity of the Aftronomer Royal, to, whofe labours the Nautical Art is much indebted for its prefent high fate of improvement; and by the Rewards held out by Parliament, 2nd the confequent improvements in inftruments for meafuring the Angular Distance, what before was confidered as nearly an impoffibility, is now come into almoft general practice. Proud of contributing my quota towards the facilitating this laudable purpofe, fo highly condu cive to the commercial interefts of this powerful Empire, I have endeavoured