340 On Currents in Water. 



the tracks of living birds from those on stone, and when among hun- 

 dreds of examples which I have seen, not one was opposed to the 

 idea of their being the veritable foot marks of birds, it seemed to 

 me that the case was a very strong one. It would be strange if I 

 should not have failed to get at the exact truth, on every minor point 

 of the subject ; especially as ray insulated situation in respect to Zoo- 

 logical collections, has prevented me from making all the compari- 

 sons which I could wish ; but 1 sjiall be happy to be corrected 

 wherever I am erroneous, even if it be in my fundamental conclu- 

 sions ; and with no little trouble, I have made such arrangements, 

 that for a reasonable return of specimens in natural history, especial- 

 ly petrifactions, I shall be able to furnish geologists, who may desire 

 them, with accurate casts of my best specimens colored so as to re- 

 semble the rock ; and probably with some specimens in the rocks ; 

 while my own specimens will always be accessible to their inspec- 

 tion ; so that if the views I have presented, are not satisfactory to 

 geologists, _ I shall at least have put within their reach, the means 

 of arrivine at the truth. 



Art. XXT. — On Currents in Water ; by Alan W. Carson. 



Whitemarsh, Montgomery County, (Penn.) 2d mo. 17, 1835. 



TO PROFESSOR SILl.lMAN.* 



About twelve months ago, I received a letter from my friend, 

 George Kenderdine, an ingenious and scientific master millwright, 

 in which he stated that Samuel D. Ingham had called his attention 

 to the circumstance, that water drawn out of a vessel, through an 

 aperture in the middle of the bottom, acquires a rotary motion in an 

 opposite direction to the apparent motion of the sun ; and stating 

 that after much thinking upon the subject, he believed he had dis- 

 covered the cause, which he explained at considerable length. With 

 his permission the letter was read at a meeting of the Montgomery 

 County Cabinet of Natural Science, and after making some enquiry 

 into the subject, it was believed that few persons had noticed the 

 circumstance of the revolutions being always in the same direction, 

 and for aught that could be discovered, it did not appear to have 



* We have retained this paper for some months, wishing for an opportunity to 

 examine the facts in the case; hut as this has not been in onr power, and as the 

 communication is well written, we conclude to give it ropm, and let it take its 

 chance with the scientific world. — Ed. 



