THE

PREFACE.

A

LTHO' there is little need of Saying any thing by way of Preface to the following Treatife, yet Custom having made it almost as necessary as an Entrance to an House; I shall so far comply with Custom as to say, That the following Directions for Surveying, &c. were put into my Hands in M. S. to be Enlarged, Corrected and Improved, in such a Manner as to make them of General Use and Easy Practice, according to the Modern, Best, and most Improved Methods in that Excellent and Useful Science.

How far and how well that Design and Purpose bath been pursued in the following Pages, I must leave to the Ingenuous Reader to judge, after I have just told him that He will meet mest

with several very useful Definitions, Axioms, Problems and Theorems, wholly new, or at least newly apply'd. Here will be found also several new Problems added, relating to the Art of Dividing Land; As also a New Method of Surveying large Tracts of Land, by Sounds as well as Sight, by Vertue of distant Explofions, first Invented and Published by those two great Genius's and Improvers of Natural Philofophy, the Learned Mr Whiston and Mr Ditton.

I shall only add, That to make this Treatise of as General Use as may be, the Reader will meet with an useful Collection of all transparent Colours proper for the Beautifying Maps, Charts, &c. which perhaps may be thought entertaining to the Curious. But if I have made the whole Easy, Natural and Intructive, I have gained my End, and the Satisfaction I aim at.

Edward Laurence.

Definitions of Right Lines apply'd to a Circle. 30-

Plane Trigonometry.

32

Practical Trigonometry.

45

Levelling of Ground.

59

The Use of the Line of Numbers.

62

Measuring.

68

६४

Surveying of Land by the Chain.

97

131

Measuring Artificers Work.

Surveying of Land by the Plane Table.

Sm veying by the Theodolite or Semi-circle. 158

Dividing of Lands.

167

Reducing Statute Measure to Customary Mea-

fure.

183

186

1১৪

_ Laying out New Lands.

Reducing of Plots.

APPENDIX.

Taking the Ground-Plot of a City or Corpora-

The Explication of the Signs and Characters used in the Treatise.

ERRATA.

AG 2. line 18, put a Period after it p. 4.1. 7, dele P B. p. 5. 1. 24, r. dividing it. p. 6. 1. 23, for these, r. two. p. 7. 1. 28, r. precede. p. 8. 1. 21, for another, r. one Point. p. 9. 1. 18, r. Octahedron. p. 9. 1. 23,r. Icosahedron. p. 12. 1. 21, r. a Line. p. 14.1.9, for whose sides, r. each fide whereof. p. 16. 1. 17, for are, r. is. p. 19.1. 13, r. Angles. p. 20. 1. 23, r. falling. p. 21. 1. 1, 7. per.. 3d Def. p. 22. 1. 11, r. 17th Def. p. 25. 1. 22, r. 13th Def. p. 28. 1. 23, r. 1 th Def. p. 29. l. 15, for may, r. was. p. 31. 1. 10, instead of for, r. from. p. 36. 1. 3, for 68.61. r. 168. 61. p. 37. 1. 15, for 22-30, r. 22°30′ P. 38. l. 8, r. 407.6. p. 39.1. 2, r. Triangle for Angle. p. 39. l. 16, r. Acute Angle b. p. 40. 1. 10, for b, r. bd. p. 41. 1. 11, for ab, r. cb. p. 42. l. 16, for 30,22, 1. 39° 22 p. 44. l. 17, for d, r. da. p. 45. 1. 2, for 639r. 63.9. P.51. 1. 9, dele and. p. 52. 1. 12, for 61°, 82', r. 61°, 32. p. 52. 1. 25, for 61, 82', r. 61°, 32. p. 54.1. 12, r. 71, 25. p. 57. 1. 17, r. Marks. p. 60. 1. 26, r. betwixt the Quarter. p. 63.1. 24, r. mentioned. p. 71. 1. 18, r. It is. p. 72.1. 19, for Br. 8. p. 88. 1. 26, for 29, r. 24. p. 89.1. 9. and 11, for 6, r. 4. p. 969 1. 2, put the Word Deductions over the two Right-hand Columns p.. 99. 1. 15, r. 198 instead of 19. p. 103. 1. 17, and 18, for Rod, r, Rood. p. 104. 1. 19, for Roots. r. Roods p. 108. 1. 26, for Circumference,r. Circumferentor. p. 113. 1. 11, r. placing. p. 127.1 14, r. Fig. 99. p. 166. 1. 9, or Arc, r. Arc of a Circle. P. 167. 1. 18, r. Circumferentor. p. 169. 1. 15, for 3 r. p. 185. 1. 12, either of the Products is.

29,

48