c 481 ] 
The following was received from Dr. Young whilst the pre- 
ceding Memoir was in the press. 
JAMES SOUTH. 
Dear Sir Park Square, 10 th July, 1826. 
I send you some computations of the Sun’s longitude 
from the observations made at Greenwich in 1820, compared with 
Delambre’s Tables, as corrected by Burckhardt and Bouvard, 
and with Carlini’s, as modified by some slight corrections com- 
municated by Professor Schumacher. The calculations have 
been made at the expense of the Board of Longitude ; and if you 
think they would tend to illustrate the subject of your Paper, 
you will perhaps have no objection to inserting them as a note 
at the end. I have had the same observations reduced by an 
able astronomer in Germany ; but the results are not immediately 
comparable with these, as they show the errors in right ascension 
only ; and they make the error of Carlini’s tables rather greater 
than is here represented, amounting to about — 8" on an average, 
instead of — 8" or + i"; so that the mode of reduction appears 
to require some further examination. 
I am. Dear Sir, 
Your faithful and obedient Servant, 
Thomas Young, M. D. 
James South, Esq. &c. &c. &c. Sec . Bd . Long . 
Date. 
Observation. 
The Sun’s Lc 
Delambre’s 
Tables improved. 
ngitude, by 
Carlini’s Tables, 
Carlini’s 
Tablesimproved. 
Error of De- 
lambre’sTables 
improved. 
Error of Car- 
lini’s Tables. 
Error of Car- 
lini’s Tables 
improved. 
1820. 
O / // 
O / // 
O / // 
O / // 
// 
II 
11 
Jan. 1 
280 3 48,2 
280 3 52,9 
280 3 47,2 
280 3 51,2 
+ 4 >7 
— 1,0 
+ 3 >° 
3 
282 6 7,9 
282 6 12,8 
282 6 6,8 
282 6 11,9 
+ 4.9 
— I, I 
+ 4 >° 
5 
284 8 27,3 
284 8 33,2 
284 8 26,8 
284 8 32,0 
+ 5>9 
— 0,5 
+ 4-7 
15 
294 20 8,0 
294 20 12,8 
294 20 6,9 
294 20 1 1,6 
+ 4>8 
— 1,1 
+ 3»6 
16 
295 21 20,0 
295 21 21,2 
295 21 15,7 
295 21 20,1 
+ 1,2 
— 4.3 
+ 0,1 
22 
301 27 51,9 
301 27 54,6 
301 27 49,0 
301 27 52,9 
+ >7 
— 2,9 
+ 1,0 
23 
302 28 52,2 
302 28 56,6 
302 28 51,1 
302 28 55,0 
+ 4>4 
— 1,1 
“|“ 2.8 
27 
306 32 47,4 
306 32 52,2 
306 32 46,7 
306 32 50,7 
+ 4 > g 
— 0,7 
+ 3>3 
3 i 
310 36 23,7 
310 36 29,8 
310 36 23,6 
310 36 28,0 
+ 6,1 
— 0,1 
+ 4>3 
