EXTRACTS FOREIGN AND DOMESTIC. 135 



The second paper was then read ; it was from Mr. C. J. W. 

 iVedderburn, Prof, of Anatomy in the Medical College oi' 

 ;.ouisiana, on the " Influence of Atmospheric Pressure on the 

 rides." Prof. W. had made observations in regard to this, in the 

 Jay of Pensacola. He observed that when the barometer ranged 

 ligh, the tides were always low, and vice versa : the ordinary mean 

 ange of the barometer was 29.50 ; the ordinary tide range was 

 rom three to four feet in the Gulf of Mexico. During a strong 

 ^. E. wind, with the barometer very low, the tide at Pensacola 

 vould be very high ; though the tendency of such a wind would 

 le to force the water out of the bay. With the wind Irom the 

 ^, W.j the tide would be very low, whilst the weather was very 

 dear; a change in the barometer to a small extent would fre- 

 uently produce a rise of from one to three feet in the tide. And 

 hus he thought a tide table might be made by which any com- 

 lander of a vessel could know by his barometer how much water 

 liere would be on the bar of a certain harbor in the Gulf; and 

 bis was of great value, because the depth of water on all the bars 

 |i the Gulf is very small, and at Pensacola it is only twenty-two 

 jjet. During N. W. winds there, they have generally "'clear 

 I'eather, with the barometer ranging high and the tides low. 

 j This was the substance of the paper. 



' The President here said ihat he had just remembered the name 

 |f a plant he had seen in a garden at Rochester, and no one knew 

 low it got there ; it was selia trifoliata ; and smelling abomina- 

 ly was called the skunk tree ; perhaps that was the mapoliie of 

 ieut. Hardy. 



Mr, Kedfield said in relation to atmospheric pressure on tides 

 lat half an inch of mercury only made a difference of six inches 



the tide. Dr. Wedderburn has overrated the matter. So in 

 le case of the N. E. winds causing high tides ; a rise in the tide 



Pensacola must be produced by some cause operating out of that 

 ly. Thus a N. E. wind at Pensacola would be an East wind at 

 ucatan, and a S. E. wind at another place, forming, as it were a 

 rcuit of winds, all tending to drive the water into the Bay 'of 

 ensacola. 



:Mr. Rogers said that some years since, great changes were ob- 

 jrved in the level of the Swiss Lakes in times of great storms ; 

 fd scientific men in Switzerland called on us to observe if there 

 be similar changes in our great northern Lakes. Here is a great 

 iuge to go by. Has any one made these observations on Lake 

 ■rie or Superior ? Is there not some other force at work, much 

 ibre than what is due to static altered pressure 1 Is there not a 

 <[namic force at work, as well as that of the change in a superin- 

 <imbent column of atmosphere ? The dynamic force of the wind 

 derating on the weaves of a lake, sustained through hours and days, 



