marint: barometer. 117 



if the mercury kept up, I stretched off, in the expectation observations 

 that it would freshen up again in a few hours. Amongst and inferences 

 +k u ,• . . . , T • XL, 1, „ to ascertain 



the barrier reets, when the wind was dying away, the baio- ^^^ correspon- 



meter told me, almost certainly, from what quarter it would dent changes 

 next spring up. If the mercury stood at 30,15, or near it ;^^Jji"e'i*°tie 

 and was rising, I expected the proper trade wind : and if expected after 

 higher, that it would be well from the southward, or would change in the 

 blo^v fresh; and if it was up to 30,30, both. The falling ^^[^_^ 

 of the mecury to 30,10 was an indication of a breeze from 

 ^the north-eastward ; and its descent below 30 inches that 

 it would spring up, or shift round to the westward. This 

 regularity of connection between the barometer and the 

 direction of the wind, is perhaps too great to be expected 

 at a dilFerent time of the year ; and it is probable, that we 

 should not have found it continue so strictly, had our stay 

 amongst the barrier reefs been much prolonged. 



5(h, Leaving the east coast in thelat. 17° south, we steered 

 oft to the northward for Forres' Strait, in the latter part of 

 October. As we advanced northward, I found the mercury 

 stand gradually lower with the same kind of wind and 

 weather. The difference was not material till vre reached 

 the latitude 13°, but afterwards, the south east wind which 

 had before kept the mercury up to 30,15, then permitted 

 it to fall to -29,90; and the winds from ENE and NNE to 

 29,85. Was this alteration owing to the want of density 

 in the air brought in by the south-east winds, in this lower 



latitude? — to our increased distance from the land ? or 



Avas it, that the south-east wind was no longer obstructed 

 by the coast, having a passage there through Torres' 

 Strait? 



The difference between the height of the mercury, daring 

 a north-east and a south-east wind, was much less here than 

 before, although the weather was most unfavourable during 

 the time of the north-east wind, and should have increased 

 the difference in their effects. Was this owing to the gene- 

 ral approximation to that equality which has been observed 



to take place in the barometer, in very low latitudes ? or 



that the north-east wind, still meeting with resistance from 

 the coast, had one cause for keeping up its power, which the 

 south-east wind had lost ? 



In a general summary of the winds on the east coast, 



those 



