Calcutta , Madras, and Bombay , in the East Indies. 427 
respects alike, the difference of longitude was found to be 
S’# 18". 
Longitude of the Madras Observatory 8o° 17' 21" 
Calcutta (Fort William) E. of the 
Observatory . . . 8 6 18 
Longitude of Fort William* . . 88 23 39 E. 
Of the Longitude of Bombay. 
In the year 1791, being at Bombay, on my way from 
England to Madras, and aware that great doubts existed as 
to the longitude of that important commercial station ,+ I pro. 
posed taking some observations, while detained there for a 
passage to this coast, with the view of assisting in the deter- 
mination of the question ; and accordingly commenced ob- 
serving the eclipses of the satellites of Jupiter, and a series of 
lunar observations ; taking also at the same time a sufficient 
number of meridianal observations for determining the lati- 
tude. The results were as follow : 
By the mean of about 160 lunar observations with a sex- 
tant by Troughton, the longitude of the place of observation 
at Bombay was 72 0 57' 39" E. ; and by the mean of 180 lunar 
observations with a sextant, having Ramsden’s name on it, 
the longitude of the place was 72 0 57' 55". The mean of 
both was 72°57 / 47". 
But it would appear from the lunar observations taken at 
* The latitude of Calcutta is considered 22° 33' N. 
f Mr. Howe’s longitude, 7 2 0 38', appearing at the time to be considered the 
most correct ; but Captain Huddart had placed it more than a quarter of a degree 
farther to the eastward. 
