OR, A

TREATISE

O F

Byam

Geometrical, Trigonometrical, Arithmetical,
Inftrumental, and Practical

NAVIGATION;

TEACHING

How to keep a Reckoning, both in Latitude and
Longitude, without TABLES or INSTRUMENTS, by
a NEW METHOD never yet Published: Illustrated
with Practical Examples of keeping a JOURNAL,
and correcting it by an Obfervation; with a New Way
of finding the Variation, and Time of High-Water at
any known Port.

All Neceflary TABLES, calculated to the New STILE, and
the Projection of the Sphere Orthographick and Stereographick.
Alfo Current Sailing, with other Pleasant Questions, and how
to Correct the Longitude by a Solar Observation.

The EIGHTH EDITION, with the Addition
of Spherical Trigonometry, and Aftronomy.

By HENRY WILSON.

LONDON:

Printed for W. and J. MOUNT, T. PAGE and SON
on Tower-Hill, M.DCC.LXI.

SHOULD have been at
a Lofs to approach your
Lordship with this DEDI-
CATION, if I had not

firft had the Honour immediately to Serve
your Honourable Father Admiral Byng,
in the Quality of Mathematician,
aboard of His Majesty's Ship the
Barfluer, in the Mediterranean
A 2

I at

the

the fame Time having the Honour to attend and affift your Lordship in your Mathematical Studies Aboard of the faid Ship, and his Lordship after his return to England, being pleafed to Accept and Approve of a Dedication of this Book of Navigation: I humbly crave Leave to do myself the additional Honour, to make an humble Offering of the fifth Impreffion to the Patronage of your Lordship, and to continue it under the fame Noble Family and Title, where it has been so much encouraged, and beg Leave to be allowed the Honour to fubfcribe myself,

My Lord,

Your Lordship's most humble,

And moft obedient Servant,

HENRY WILSON.

HE general Approbation that this Book has meet with, both in the T Navy and amongst Merchant Ships, hath encouraged the Bookfeller, not

only to print a large Number, but alfo to be at the Charge of the Addition of Spherical Trigonometry, Aftronomy, &c. and engraving all the Cuts upon Copper-Plates, with