MARINE BAROMETER. l'/"i 



The principal difTerences in the effect of v/Inds upon this Observation» 

 coast, from what they produced upon the south and east coasts, ^^^ inference* 

 • ' 1 . 1 I !• 1. -r to ascertain the 



ate, that a north-east wind raised the mercury as high, it not correspondent 



higher, than one from the SE ; and that a north-west wind, changes of 

 where it came from off the sea and was moderate, was equarJ to t)-,gp^ ^^ Y,e ex- 

 either of them, and kept it up higher than the south-west pected after 

 wind did. '^^"''"se in the 



iiiiA v^iu. ^ marine baro- 



In order to h.ave ascertained the full effects of sea and land meter. 

 iVinds upon the barometer, it was desirable to have learned, 

 whether the south-east winds, which occasioned the mercury 

 to rise highest upon the south and east coasts, would have left 

 it at the medium standard, or made it descend upon the north- 

 west and west coasts of Australia; but, unfortunately, the state 

 of the ship did not permit me to determine this ; for at the dis- 

 tance we kept from these coasts^, in mak'ng the best of our 

 Way to Port Jackson, the accumulation of air over the shore, 

 arising from a sea wind, or the contrary from a land wind, can 

 scarcely be supposed to have much, if any eflfect. The princi- 

 j)al winds we experienced between Timor and Cape Leuwen, 

 in the months of April and May, were from SE and SW. The 

 sbUth-east wind prevailed as far as the latitude 25", and the 

 mercury stood at first with it at 29,95 ; but as we advanced 

 southward, it rose gradually to 30,25, nearly iri the same way 

 as it had before descended on the east side of Australia, when. 

 we steered northward in the month of October. This wind 

 was succeeded by an unsteady northwardly wind, which 

 brought the mercury down to 29,90 ; but on its veering by the 

 ■west to SW it ros(i fast, and fixed itself about 30.32 : we were 

 then drawing near Cape Leuwen. 



As far as this example can be admitted in proof, it appears, 

 that a wind from the SW has an equal, if not a superior power 

 to one at SE in raising the mercury upon the west coast; 

 which was not the case upon the south, and still much less 

 upon the east and north coasts, where the south-west wind 

 caused it to fall. Winds from the northward caused the mer- 

 cury to descend, as 1 belive they always will in the southern 

 hemisphere, if not obstructed by the land ; but upon the north 

 coast, we have seen the mercury stand higher with it than al- 

 most any other. 



Upon a summary of the effect; of the same winds upon the 

 Vol. XVL-March, 1807. S different 



