on the Marine Barometer. 
247 
gale, however, there was a pretty rapid descent in the baro- 
meter to 29,96 ; but the ascent again was equally rapid, and 
to a greater height, on the wind becoming moderate. In a 
short calm that succeeded, the mercury stood at 30,42, but 
on the wind setting in from the north, which was from off 
the land, it fell to 30,25, and remained there two days : we 
had then reached Bass' Strait. 
From these examples upon the south' coast, it appears, ge- 
nerally, that a change of wind from the northern, to any 
point in the southern half of the compass, caused the mercury 
to rise, and a contrary change to fall ; and that the mercury 
stood considerably higher when the wind was from the south 
side of east and west, than, in similar weather, it did when 
the wind came from the north side ; but, until it is known 
what are the winds that occasioned the mercury to ascend, 
and what to descend, upon the other coasts of Australia, it 
will probably be not agreed, whether it rose in consequence 
of the south winds bringing in a more dense air from the 
polar regions, and fell on its being displaced by that which 
came from the Tropic; — or whether the rise and higher 
standard of the mercury was wholly, or in part, occasioned 
by the first being sea winds, and the descent because those 
from the northward came from off the land. 
The height, at which the mercury generally stood upon 
the south coast, seems to deserve some attention. It was very 
seldom down to 29,40, and only once to 29,42. Of one hun- 
dred and sixty days, from the beginning of December to 
May, it was nearly one-third of the time above 30 inches ; 
and the second time of passing along the coast, from the 15th 
of May to the 1st of June, it only once descended to 29,96, 
MDcccvr. K k 
