better than me, if any Thing in them be valuable or not; every man being apt to be biaffed in favour of his own Productions, which oftentimes may be good for little,

Advertisement.

Advertisement,

Have almoft prepared for the Prefs a Treatife of geometrical and mechanical Constructions of Problems, with the after-written Title, which I intend to publifh, if I can meet with suitable Encouragement, and can get enough Hands to defray the Expence, by Way of Subfcription, from Gentle men who delight in this Study, and are willing to promote fuch a Work.-The Book will be an Octavo, and its Price not more than Six Shillings. But the Subfcribers need not pay down any Thing till the Book be delivered.

Gentlemen may fee a Specimen of this Work, and subscribe for it, at Mr. PAYNE'S, Bookseller.

The BOUNDARIES of GEOMETRY enlarged, and its Practice made easy.

CONTAINING

The Conftructions of many useful Problems, plain, folid, and linear; pointed out by the Nature of the Problems themselves, without the Help of Algebra, or any great and burthenfome Remembrance of the Nature and Properties of Figures, either plain, curve-lined, or folid, except a few of Euclid's Propofitions, and half a Dozen of the principal Properties of the Three Conick Sections; and executed by a few fimple and common Inftruments, without Reference to any other Treatise.

1.

ERRAT A.

Page 3. line 41. for Def. 5. r. Def. 6. P. 25. 1.7. for the Angle ACD, r. the Angle BCD. P. 27. 1. 15. r.. Centre. P. 28. 1. 9. r. Euclid. P. 64. 1. 17. for DF, r. EF. P. 65. 1. 2. for des, r. Sides. P. 108. 1.9. for right-angled, r. right-lined. P. 127. l. 12. for the Angle ABC, r. the Angle ACD. P. 150. 1. 13. for Angle, r. Angles. P. 158. 1. 23, 24. for oppofites, r. oppofite. P. 216. 1. 17. the Letter M wants a Stop after it. P. 225. 1. 16. r. magnitudes. P. 411. 1. 2. for xx3 r. zxx. P. 427. 1. 26. for Triangle, r. Triangles. P. 429. at the Bottom, dele the word without. P. 434. 1. 23. 31. for Equimultiples, r. Multiples. P. 436. 1. 13. 25. 27. for Equimultiples, r. Multiples. P. 444. for Addition, r. Additions. P. 447. the Letter E is wanted in the Fig. P. 448. 1. 21. for Figures, r. Figure. P. 451. 1. 18. for folid fimilar, r. fimilar folid. P. 441. at the Top, for Book III. r. Book VI. P. 443. at the Top, r. Book XII. P. 446, 447, 448. at the Top, r. Book VI. P. 452 453. at the Top, T. Book XI.