of ike Barometer lettccen the Tropics. 293 



four days in gettiug clear of the river, in which time the 

 mercury inclined to be stationary, excepting that a small in- 

 clination towards the equatropical motions seemed to evince 

 itself at times. But no sooner had \vc cleared Canton river, 

 September 13th, 1803, than the mcrcnr}' in the barometers 

 began to conform to the equatropical motions, of two ele- 

 vations and two depressions every twenty-four hours, at 

 equal intervals of time, (although we were near the land 

 luitil the 15th of September.) " And the mercury, with 

 great regularity, continued to perform the equatropical 

 motions from September 1 3th, 1803, the day we cleared the 

 river of Canton, until October 13, when we entered Sin- 

 capore strait, excepting a small degree of irregularity, 

 which affected the mercury on the 22d of September, when 

 it blew a gale on the coast of Isiompa. 



October 13th, 1S03. On entering the strait of Sincaporc, 

 which is about three leagues and a half wide, the mercury 

 in the barometers was then a little obstructed, and did not 

 perform the equatropical motions in the same quantity of 

 rise and fall as when we were in the Cliina sea. Eut on 

 the following day, October Mth, when we had passed the 

 narrow part of the strait, the mercury confornicd to those 

 motions with regularity until October 21st, when we arrived 

 in the harbour of Prince of Wales's Island: then a great 

 retardation look place in the equatropical motions; for, 

 during the lime the ship remained in the harbour, from 

 October 20th to November 3th, 1803, the niercury in baro- 

 meters seemed only in a small degree subject to them, the 

 difference between the high and low stations of the mercury 

 being in general not more than half the quantity that takes 

 place in the open sea, or at a considerable distance from 

 land. Where the ship lay at this time in the harbour, the 

 land, on one side, was a full quarter of a mile distant, and 

 on the other tide about a mile and a half. 



On November 5th, being clear of the harbour of Prince 

 of Walcb's Island, the equatropical motions were in'staiitly 

 performed by the mercury in the usual quantity experienced 

 at sea, which continued uith uniformitv until December 3d. 

 On this and the following day the mercury fell considerably 

 during our passage over the tails of the sands at the entrancv 

 of Hoogly river in latitude 21" OG' north; and on Decem- 

 ber 5th, the day of the moon's last quarter, a gale of wind 

 commenced from north-norlh-ea>t, with nuich lightning 

 and rain in the night. During the latter part of this day 

 the mercury began to rise, and there soon followed a change 

 of settled weather. When we were in the lower part of 

 T3 \U, 



