124 Lieut . Foster’s corrections to the reductions of his 
Table X. page 223 ; Part IV. for 182 6. 
Observations for determining the apparent altitude of u Aquilas at the time of setting, by 
Lieutenant Foster’s upper telescope 
The corresponding observations for refraction are contained in Tables XI and XII; pages 224 and 225 in Part IV. for 1826. 
Correction for 
Apparent Altitude 
1825 . 
No. 
of 
Obs. 
deduced from the 
Bar. at 
Time . 
Mean readings of 
four Verniers. 
Apparent 
zenith distance. 
apparent zenith 
distance in the 
Temp. 
+ 4 8 °- 
Temp. 
Fah. 
Day. 
Winds true. 
Remarks, 
Index. 
Level. 
ratio of the No. 
of observations. 
tii 
at 1 1 h A. M. 
i| P. M. 
8 
H 
O • a 
O 
• // 
O / // 
0 / „ 
Inches. 
O 
Jan. 27 
323 7 57-5 
* 78 38 30 
0,0 
+ 0 10,9 
+ I 29,92 
85 23 31,05 
85 23 43,03 
1 4 36 22,10 
29,970 
— 29-5 
J 
Occasionally 
squally. 
Feb. 8 
( 
11 A.M. 
8 
323 8 20 
0,0 
— 0 5,45 
85 23 31,82 
4 36 22,02 
29-455 
— 22,5 
J North, 
— 
2 P. M. 
8 
*286 18 5 
— 
+ 0 8,17 
85 23 44,15 
5 moderate 
9 
10 A.M. 
8 
323 8 1,25 
0,0 
-f 0 32,7 
85 23 34,24 
J 
4 36 19-17 
29,701 
— 35-7 
) Calm,fine 
1 P. M. 
H 
*115 32 16,25 
— • 
+ 0 24,52 
8 S 23 45,77 
1 
3 and clear 
10 
ioi A.M. 
11 P. M. 
6 
6 
* 152 21 51,25 
* 3°4 43 41 >25 
" T " ■ 
+ 0 35,42 
— 0 21,80 
8 5 23 44,44 
8 5 23 34,70 
i 
4 36 20,43 
30,100 
- 35-5 
Calm 
I 5 
11 A.M. 
12 
* 304 43 8,75 
— 
+ 0 27,25 
8 5 23 38,0 
4 36 22,00 
29,600 
— 33 
Cloudy overcast weather, 
28 
11 A.M. 
i£ P. M. 
6 
6 
'* 152 22 1,25 
* 3°4 43 25 
— 
— 0 38,15 
+ 0 10,9 
8 S 23 33- 8 5 
8 S 23 35,77 
-£4 36 25,19 
29,992 
— 21 
N. E. light, clear, & fine, 
Mean to be used in Table XI. . =43621,82, instead of 43623,08 
Micrometrical measure between Telescopes as before + 3 8,42 
Altitude to be used in Table XII =4 39 30,24, instead of 4 39 31,50 
J 
The principal vernier not reset to zero, and the* observations ate continued 
from the preceding reading. 
P. S. It is to be regretted, that the observations by Lieu- 
tenant Ross, given at the end of the Paper alluded to, must 
now be wholly rejected ; in consequence of the original 
observations involving the erroneous datum dependent upon 
the level, having been left on board the Fury at the time of 
her loss. 
The extremely low temperature of the atmosphere, in 
