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The observations made by our author upon the north coast are 

 next detailed. The chief differences in the effects of winds upon this 

 coast, from what they produced upon the south and east coast, are, 

 that a north-east wind raised the mercury as high, if not higher, than 

 one from the south-east ; and that a north-west wind, when it came 

 from off the sea, and was moderate, was equal, in the above effect, 

 to either of them, and kept the mercury higher than the south-west 

 wind did. 



Upon considering the effects of the same winds upon the different 

 coasts of Australia, as described in the foregoing summary of Capt. 

 Flinders's observations, the following queries seem, he says, to present 

 themselves : 



Why do the winds from the north and north-west, which cause 

 the mercury to descend and stand lower than any other upon the 

 south and east coasts, and also in the open sea, and in the south- 

 west bight of the Gulf of Carpentaria, make it rise upon the outer 

 part of the north coast with the same or even worse weather ? 



Why should the north-east wind, which occasions a fall in the ba- 

 rometer, upon the south coast, considerably below the mean standard, 

 be attended with a rise above the mean upon the east and north coasts ? 

 The south-east wind, upon the south and east coasts, causes the mer- 

 cury to rise higher than any other ; why has it not the same effect 

 upon the north coast and upon the west ? 



How is it that the south-west wind, which makes the mercury rise 

 and stand high upon the south and west coasts, causes.it to fall be- 

 low the mean standard upon the east coast, and, with the same wea- 

 ther, to descend lower than any other upon the north coast ? 



The answer to these questions Capt. Flinders considers as suffi- 

 ciently obvious ; in support of which opinion he offers the following 

 explanation : 



The lower air, when brought in by a wind from the sea, meets 

 with resistance in passing over the land ; and to overcome this re- 

 sistance, it is obliged to rise and make itself room by forcing the 

 superincumbent air upwards. The first body of air which thus comes 

 in from the sea, being itself obstructed in its velocity, will obstruct 

 the second ; and this will therefore rise over the first, in like manner, 

 to overcome the obstruction : and as the course of the second body 

 of air will be more direct towards the top of the highest land it has 

 to surmount than the first was, so the first part of the second body 

 will arrive at the top before the latter part of the first body has 

 reached it ; and this latter part will not be able to pass over the top, 

 being kept down by the second body and the successive stream of 

 air, whose velocity is superior to it. In this manner an eddy or body 

 of compressed air will be formed, which at first will occupy all the 

 space below a line drawn from the shore to the top of the highest 

 land ; but the succeeding bodies of air, at a distance from the shore, 

 will soon feel the effect of the obstruction, and will begin to rise ; 

 by which the stratum of lower air will be deeper between the top of 

 the land and the shore, and to some distance from it, than upon the 



