426 Mr. Goldingham on the geographical situation of 
vations ; those formerly taken,* differing from the mean of 
the whole little more than half a second. The mean of the 
whole, 13° 4' 9", iff may therefore be considered, for the 
present at least, the latitude of the Observatory. 
It will be observed, that the meridianal observations of the 
sun give a different result from those of the stars. In mine, 
this difference is about 4 seconds less than by the stars ; 
in the second series, the difference is nearly 9 seconds also 
less than by the stars ; a difference not easily accounted for. 
It is curious however to remark, that the correspondent 
meridianal zenith distances of the sun at Greenwich, give a 
result greater than the mean latitude b}' the sun 5", 85 ; and 
the same elements are used in both cases, with the exception 
of declination. 
Of the Longitude J of Calcutta. 
By a series of correspondent eclipses of the satellites of 
Jupiter, taken in Fort William, by the late Lieutenant-Colonel 
Colebrooke, of the Bengal Establishment ; the telescope 
at the Observatory, and that used at Calcutta, being in all 
* The observations being so numerous, in the conclusions now drawn from mine, 
the method of selection used with the eclipses has been adopted, viz. by taking a 
mean of the whole, and then rejecting those results which differ more than the power 
of the instrument would seem to warrant : this, with the sextant, I have considered 
10", with the circular instrument 8", and with the zenith sector 4". The latitude 
formerly deduced stood thus : mean of the observations with the zenith sector 
1 3 0 4' 8",55 ; with the circular instrument 1 3 0 4' 8",40 ; with the circular instrument 
and sextant 1 3 0 4' 8",5 ; mean 1 3° 8",48 or not one-tenth of a second different 
from the result now deduced by these observations. 
f Fort St. George Church Steeple is 36" N. of the Observatory. Latitude of the 
Steeple is therefore 13 0 4' 45" N. 
J According to Rennell’s Memoir, the Longitude by the Honourable Thomas 
Howe, was 88° 33' ; by mean of four observers, 88° 27' 45". 
