On the Tides. 81 



Art. V. — On tlie Tides ; by David Tomlinson. 



Schenectady, Aug. 1st, 1837. 



TO PROF. SILLIMAN. 



Dear Sir, — -I have read with much pleasure, several ingenious 

 strictures on storms of wind, by W. C. Redfield, as published in 

 former numbers of your useful Journal of Science. 



In your No. II, for July, 1837, in his remarks on this supposed 

 connection of the Gulf stream, " with opposite currents on the 

 coast of the United States," he says, " the Gulf stream, in its 

 course from Florida to the banks of Newfoundland, is for the 

 most part imbedded or stratified upon a current which is setting 

 in the opposite direction in its progress from the polar region- — 

 that their opposite courses on the coast while in contact with each 

 other, are no more surprising or inexplicable than the case of two 

 opposite currents of the atmosphere, and the latter are often known 

 to maintain opposite courses for a long period, and at high velo- 

 cities, while thus superimposed one upon the other." 



The different currents of the atmosphere are often rendered 

 visible, by the courses of fleecy clouds ; but, that contrary and 

 rapid currents, of so dense a fluid as water, should be "imbed- 

 ded," one in the other, appears to contradict the laws of friction, 

 impulse, and motion. 



I am aware it has been said, that, at the straits of Gibral- 

 tar, where from the Atlantic ocean a strong and regular current 

 always flows into the Mediterranean sea, this current is caused 

 or balanced by an under or contra one at the bottom, flowing 

 equally swift outward into the ocean ; and that this has been 

 proved to be true by the wreck of a vessel known to have been 

 lost in the Mediterranean sea, having been seen in the Atlantic 

 ocean ; but a single instance is not conclusive ; for, if it were the 

 same wreck, a strong east wind might have driven it out. 



I know the danger of suggesting any thing in opposition to es- 

 tablished opinions of great and learned men ; for instance, in op- 

 position to the opinion, that the moon is the cause of the flowing 

 and ebbing of the tides. That the attraction of the moon regu- 

 lates the times of the tides caused by the Gulf stream, after their 

 becoming into existence and being set in motion, is evident ; 

 but that the flowing and -ebbing is wholly caused by the moon, 



Vol. XXXIV.— No. 1. 11 



