diurnal Variation of the Barometer between the Tropics. 185 
at which time it comprises the observations of 22 months, 
having commenced April 6th, 1802, in Margate Road. 
I have taken the liberty of sending you this abstract from 
the journal, to exhibit the apparent difference of the mercury 
in the barometer at sea, from what has been observed on shore, 
at those places mentioned in the preceding description. As I 
have not seen any account indicating the phenomenon, I 
thought it might be interesting to you, or other gentlemen of 
the Royal Society to forward this imperfect abstract, the 
journal itself being too cumbersome to send home at present. 
But as I am in expectation of returning to England by the 
ships from China next season, I hope I shall be enabled to 
present you with the meteorological sheets alluded to above. 
I am, &c. 
J. HORSBURGH. 
P. S. Since I wrote the foregoing abstract, I have received 
a letter from my friend Mr. Dalrymple, intimating that a 
copy of the meteorological journal itself would be acceptable, 
which has induced me to transmit to him the original sheets, 
with a request to deliver them to you. I regret that I could 
not find leisure time to make out a fair copy, to have sent 
to you, in place of the original sheets in their rough state. 
Bombay, 
June 1 st, 1804. 
B b 
MDCCC V. 
