Appendix B. 
Fort Portal. — 22nd July, 
19 h 
53 m 
. Obs. No. 78 ; 
K x 
- 3 h 15 m 18 s ' 
■8 
22nd „ 
19 
55 
„ 79; 
J 5 
20 • 
■ 1 
23rd „ 
20 
6 
GO 
o 
J ? 
22 ■ 
• 6 
23rd „ 
20 
8 
„ 81; 
J) 
= 22 
■ 2 
Of this the mean for the double series required by the above-mentioned 
inversion of the glass roof of the artificial horizon is : 
21st July, 
4 h 15 m 
K 1= +3 h 15 m 16 s -0 
21st „ 
19 54 
5J ~ + 
17 -0 
22nd „ 
19 54 
J9 = + 
19-5 
23rd „ 
20 7 
?J = + 
22 • 4 
Referring these values to the date coinciding with the first of them, and 
noting the hour indicated by the chronometer, we get: 
21st July (civil)—(p.m.): t c - 10 h 57 m 49 s ...K^S' 1 15 m 15 s, 8 
as the mean on Greenwich mean time. 
From the determinations of the time at Bujongolo on the 10th, 11th, 
and 12th July (astronomic dates), the results of which have been given at 
p. 312, we obtain the absolute correction of No. 1 chronometer. Referring all 
the values to the date of the last, and passing from the absolute correction 
of the chronometer to the absolute correction on Greenwich, we get: 
13th July (civil)—(a.m.): t c = 2 h 51"’ 6 s ...Ki = 3 h 15 m 28 s '4 
from which in the interval between the 13th and 21st July the daily correction 
of the chronometer is found to be : 
K 1 = - I s -521. 
As already stated at p. 315, on the return journey the chronometers at 
Fort Portal varied considerably through lack of control, so that, before leaving 
this place, we proceeded to the determination of their correction by means of 
six series of altitudes, the results being: 
27th July. —Obs. No. 82 ; t e = 10 h 20 ra 11 s ... = + 3 h 32 m 57 s - 6 
27th „ „ 83; „ —10 23 0 „ = 51 '0 
28th „ „ 84; „= 2 21 0 „ = 59-5 
28th „ „ 85; „ = 2 23 8 „ = 59 • 9 
31st „ „ 87; „ = 10 25 44 „ = 64 • 8 
31st „ „ 88; „ = 10 27 53 „ = 64 ■ 7 
The disagreement of the second series induced us to abandon it, the 
influence of some error in the observations being obvious. 
316 
