i?9

in Mechanics and Physical Astronomy.

ing on the moon’s distance from the fun’s apogee andthe latter, an equation something more considerable, whose ar-gument is the distance of the moon’s apogee from that of the fun.

By having shewn above, that the effect of such terms, orforces, as are proportional to the cosine of the arch z, is expli-cable by means of the co-sines of that arch, and of its multiples,(no less than the effects of the other terms that are proportio-nal to the co-fnes of the multiples thereof) a very important pointis determined: For, since it appears thereby, that no terms enterinto the equation of the orbit but what by a regular increase anddecrease, do after a certain time return again to their formervalues, it is evident from thence, that the mean motion, andthe greatest quantities of the several equations, undergo nochange from gravity.

THE END.

errata.

Page 5 line 18, for R read R'j 1. 21, for R' r. R; p. 30. 1 .9, for ha-\-bh r>ha+b ; 1. 13, for t r. h; p. 39.1. 14, put the comma before -vO^-; p. 58. 1.

11, for PSO r. PSC j p. 59. 1 .15, for — r. —; 1. 22, for F r. N; p. 114,

2a a

1 . 32. r. powers of; p. 127, 1 . 9, for AGO r. AOG ; p. 128. 1 . 30, for BL.BR; p. 131. 1 . 23, for BC r. »C; p. 138. 1 . 15, iocEcf r. Ee; p. 143, 1 .

BC BC

15 dele to-, p. 152, 1. 2, for r. yy, p. 160. 1. 27, for — r. —.

In fig. 18, at the intersection of the circumference of the circle and the right—line Em, place an c.

U. *