XXX11 
APPENDIX. 
Memorandum annexed to the Lunar Observations of June and August. 
The difference of the chronometers on Greenwich time having been care- 
fully noted on the sixth of May, the day preceding their embarkation from 
London, the lunar observations of June and August afforded a means of 
ascertaining their rates since they had been on board. 
1st. By 640 distances of the sun west of the moon observed in June, No. 
228 was found slow 3 m 44 s .35 of Greenwich time at noon of the 29th of 
June ; when the differences of the other five chronometers, obtained by com- 
parison with 228, were also as follows : 
254 259 369 404 25 
ms ms ms ms ms 
Slow 1 42.3 slow 4 33 slow 0 28 fast 6 52 fast 11 17.5 
2d. By 569 distances of the sun east of the moon observed in August, the 
chronometers were found to differ from Greenwich time at noon of the 14th of 
August, as follows : 
228 254 259 369 404 25 
ms ms ms ms ms ms 
Slow 2 43 slow 3 12 slow 6 45.75 fast 0 30 fast 7 58 fast 18 57.5 
The mean of these differences of the 29th of June and of the 14th of August, 
being taken as the correction for each chronometer to Greenwich time at noon 
of the intermediate day, viz., the 22d of July, the errors incidental to results 
obtained from distances exclusively east, or exclusively west of the moon, 
may be considered to be nearly balanced. 
Corrections to Greenwich time on the 22d of July. 
228 254 259 369 404 25 
ms ms ms ms ms ms 
Slow 3 13.67 slow 2 27-15 slow 5 39.4 fastO 01 fast 7 25 fast 15 00.75 
By comparing these corrections with the original differences at midnight on 
the 6th of May, (Appendix, page xiii.) the gain or loss of each chronometer in 
the interim is obtained, and thence its daily rate, by dividing by 76|, being the 
number of days comprised in the interval : 
228 
254 
259 
369 
404 
25 
Mid*. May 6. SI. 2 26.85 si. 0 28. 15sl. 0 38.85 fa. 1 56.15 fa. 4 55.9 fa. 3 25.15 
Gain or loss. L 0 46.82 L2 55.3 L5 00.5 LI 55.15 G2 29.1 G 11 42.35 
Per diem. L 0.612 L 2.29 L 3.9 L 1.5 G 1.95 G 9.18 
