26 PLACEofaPLANET&c. 



Log. 

 Coffip. to i8o"=«=59'' 59' 59"-62 cof. .5000015.9=. 6989714 

 — x= .0167923. 



.4832092.9 = .6841352 

 difF. = . 0148362 

 Cotang. 59° 59' 59". 62 = 9. 7614 412 

 9.7466050 

 + 613 



Tang. 29'' 9' 48" = 9.7466663 

 + 90 

 True anomaly 119" 9' 48' 

 Mean anom. 1 20 50 00 

 Equation — 1° 40' 1 2 " 

 If the I ft and 6th 60° of mean anomaly in the Earth's orbit 

 be computed by the firft feries, the 3d and 4th 60" by the fecond 

 feries, and the 2d and 5th by the lart; feries, no more than the 

 firft 3 terms containing powers of z, need be ufed, for the 

 equation cannot be had true to -^ of a fecond without tables of 

 logarithms carried farther than to 7 places. 



N°. IV. 



On the Improvement of Time- keepers, by David Rit- 

 TENHOUSE, L. L. D. Prejident of the Society. 



Read Nov. 'THHE inventioii and conftruftion of time- 

 7, 1794- X keepers may be reckoned amongft the moft 

 fuccefsful exertions of human genius. Pendulum clocks 

 efpecially, have been made to meafure time with afto- 

 nifhing accuracy ; and if there are ftill fome caufes of 

 inequality in their motions, the united efforts of me- 

 chanifm, philofophy and mathematics will probably in 

 time remove them. 



The lafl and leaft of thofe caufes, which perhaps may 

 l?e worthy of notice when all others of more importance 



are 



