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Observations upon the Marine Barometer, made during the Examina- 

 tion of the Coasts of New Holland and New South Wales, in the 

 Years 1801, 1802, and 1803. By Matthew Flinders, Esq. Com- 

 mander of His Majesty's Ship Investigator. In a Letter to the 

 Right Hon. Sir Joseph Banks, Bart. K.B. P.R.S. &.C. SfC. $e. 

 Read March 27, 1806. {Phil. Trans. 1806, p. 239.] 



The chief circumstance that induced Capt. Flinders to think his 

 observations upon the marine barometer were worthy of attention, 

 was the coincidence that took place between the rising and falling 

 of the mercury, and the setting in of winds that blew from the sea 

 and from off the land, to which there seemed to be at least as much 

 reference as to the strength of the wind or the state of the atmo- 

 sphere. 



Our author's examination of the coasts of New Holland and the 

 other parts of the Terra Australis, began at Cape Leuwen, and con- 

 tinued eastward along the south coast. His observations, which, on 

 account of their length, we must pass over, show, that a change of 

 wind from the northern half of the compass to any point in the 

 southern half, caused the mercury to rise; and that a contrary 

 change caused it to fall. Also, that the mercury stood considerably 

 higher when the wind came from the south side of east and west, 

 than when, in similar weather, it came from the north side. 



Capt. Flinders now proceeds to relate the observations he made 

 upon the east coast. From these it appears that the winds which 

 came from between south and east caused the mercury to rise and 

 stand high, as the same winds had done, with only one exception, 

 on the south coast. The wind from north-east kept the mercury up 

 above thirty inches on the east coast, and caused it to rise after all 

 other winds, except those from the south-east ; whereas, on the south 

 coast, those winds caused the mercury to fall, and to stand much be- 

 low thirty inches ; owing, in our author's opinion, to the wind coming 

 from off the land. During north-west winds, the mercury stood lower 

 upon both coasts than at any other time ; and, on both, those winds 

 came from off the land. 



Moderate winds from the south-westward, with fine weather, 

 caused a descent of the mercury on the east coast ; and during their 

 continuance, it was much lower than with winds from the north- 

 eastward ; but upon the south coast it rose with south-west winds, 

 and it stood much higher than with winds from the opposite quarter. 

 But it must be observed, that the wind which blew from the sea 

 upon one coast came from off the land on the other. 



The mean height of the mercury on the east coast is stated by our 

 author to be not less than 30'08 or 30*10 inches ; whereas upon the 

 south coast he estimates its mean height to be 30 inches. The greatest 

 range observed upon the east coast was from 29'60 to 30'36 ; while 

 upon the south coast the range was from 29-42to30'51. But it 

 must be remarked, that these extremes are taken for very short in- 

 tervals of time. 



