THE

CONTENTS.

СНАР. I.

Navigation Geometrical.

ECT. 1. Geometrical Problems.

SECT.

Page 1

Sect. 2. The Conftruction of the Sines, Tan-

gents and Secants.

Plane Trigonometry Geometrical.

3

Sect. 3.

7

Sect. 4.

Oblique Trigonometry Geometrical.

10

Sect. 5.

Plane Sailing Geometrical..

12

Sect. 6.

Traverse Sailing Geometrical.

15

Sect. 7.

Mercator's Sailing Geometrical.

20

Se&t. 8.

Parallel Sailing Geometrical

25

Sect. 9.

Middle Latitude Sailing Geometrical.

30

CHA P. II.

Navigation Trigonometrical.

ECT. I.

SECT. Plane Trigonometry.

Sect. 2. Oblique Trigonometry.

Sect. 3. Plane Sailing Trigonometrical

Page 35

40

43

Sect. 4. Mercator's Sailing Trigonometrical, with a

Method for fupplying the Table of Meridional

Parts.

52

Sect.

Sect. 5. Parallel Sailing Trigonometrical. Page 62

Sect. 6. Middle Latitude Sailing Trigonometrical 65

Sect. z. Traverse Satling by Inspection.

77

Sec. 3. How to find the Difference of Longitude by

Inspection in the Traverfe Table.

CHA P. IV.

Navigation Arithmetical.

86

89

ECT. 1. Plane Sailing Arithmetical.

Sect. 2. Mercator's Sailing Arithmetical. 100

SE

Sect. 3. Parallel Sailing Arithmetical.

Sect. 4.

Middle Latitude Sailing Arithmetical. 119

CHAP. V.

Navigation Inftrumental.

SECT. 1. Plane Sailing Inftrumental.

130

Sect. 2. Mercator's Sailing Inftrumental. 136

Sect. 3. Parallel and Middle Latitude Sailing In-

ftrumental.

139

СНАР.

С НА Р. VI.

A New Method for folving any Quef-

tion in Plane Trigonometry, and

keeping a Reckoning both in Longi-
tude and Latitude, without Book,
Table, or Inftrument, &c. only with
Pen and Ink.

SEC

143

ECT. 1. Rules and Grounds of the Method p. 140

Sect. 2. Plane Sailing by a New Method

Sect. 3. Oblique Triangles, folved by the New

Method

150

Sect. 4. How to find the Difference of Longitude by

the New Method

156

CHAP. VII.

Practical Navigation, or the Applica-

tion of the foregoing Rule, to the

actual keeping of a Reckoning, &c.

SE

How to find the Variation of the

161

ECT. 1.
Compass by an easy Method

Sect. 2. How to divide a Log-line, and prove a

Half-Minute Glass

163

Sect. 3. How to make a Plane Chart, and alfo a

Mercator's-Chart, and a True Plane Chart 167

Sect. 4. How to take and work an Obfervation 175

Sect. 5. How to know the Time of High-Water at

any known Port, only by a Sight of the Moon, at

any

any Time of the Day or Night; with probable

Reafons for the Original Caufe of the Ebbing and

Flowing of the Sea, with a Table of the Moon's

Changing for 15 Years.

Page 179

A Tide-Table.

196

Sect. 6. Examples in keeping a fournal, and how
to give all proper Allowance for Lee-way, Variation,
&c. and bow to correct it by an Obfervation.

CHAP. VIII.

Of the Projection of the Sphere.

202

SECT. 1. Of the Orthographick Projection 219

Sect. 2. Of the Stereographick Projection 225

Sect. 3. Of Spherical Trigonometry Right-angled 236

Spherical Trigonometry Oblique

A

TABLES

In the Second PART.

244

Tabe of Difference of Latitude and Departure 257

A Table of Meridional Parts

Tables of the Sun's Declination

279

289

A Table of the Latitude and Longitude of Places 298

A Table of the Sun's Right Afcenfion

A Table of the fixed Ștaxş

of Currents

Pleasant Questions

To find the Longitude

Aftronomy

316

茶茶

NAVIGATION

New Modell'd.

CHAP. I.

NAVIGATION Geometrical.

SECT. I.

Geometrical Problems.

PROB. I. From a Point given in the Middle of a Line, to erect a Perpendicular.

ITH your Compaffes opened at any Extent, and one Foot in the given Point A, make the Marks b and c, then with any greater

Extent, and one Foot in b, make Fig. 1. an Arch, as at d, and with the fame

Extent, and one Foot in c, crofs the faid Arch at d; then from the croffing of the faid Arches to the Point A, draw a Line, it is the Perpendicular required.

PROB. II. From a Point given above a Line, to let fall a Perpendicular.

With your Compaffes opened at any Extent (more than the nearest Distance from the given Point to the given

B

Line)