diurnal Variation of the Barometer between the Tropics. 181 
the equatropical motions, and continued them with great uni- 
formity, during our passage down the Malabar coast, across 
the bay of Bengal, in the Strait of Malacca, and through the 
China Sea, until our arrival in Canton river on the 4th of 
October. When in the river, the mercury became nearly sta- 
tionary during the 24 hours, except a small inclination at times 
towards the equatropical motions, but they were not near so 
perceptible as at sea ; this change taking place the day we got 
into the river. 
During our stay in China, the barometer on shore, at Canton, 
had very little tendency towards the equatropical motions, 
throughout the months of October and November that we 
remained there. At times, while in China, a small inclination 
towards performing the equatropical motions appeared : but, 
as in Bombay, the difference of rise and fall was of so small 
a quantity, as to be frequently imperceptible. 
December 2d, 1802. On our departure from Canton river, 
the equatropical motions were instantly performed by the 
mercury, and with great regularity continued during the whole 
of the passage to Bombay, until our arrival in that harbour on 
the 11th of January, 1803. 
On January 18th, the barometers were placed on shore, and 
did not appear in the smallest degree subject to the equatro- 
pical motions ; although, with great regularity, they had been 
performed while at sea, even to the day we entered the harbour. 
One of the barometers was left on board for a few days, and, 
like that on shore, seemed to have no tendency towards 
the equatropical motions. During the months of February 
and March, in Bombay, the mercury was nearly stationary 
throughout the 24 hours. But about the latter part of March 
