22 Professor Eaton on a singular deposit of GraveU 

 Art. III.^ — On a singular deposit of Gravel; hy Professor 



A. Eaton* 



TO PROFESSOR SILLIMAN. 



Sir, 



I HAVE just taken the measure of a deposite of several 

 hundred cart-loads of gravel, made by the nver Hudson, on 

 Mondayj the 4th Inst, thirty-four feet higher than the high- 

 est point to which it rose during the time of making the de- 

 posit. This apparently paradoxical statement may if par- 

 ticularly described, and deposited among other facts in your 

 scientific store-house, contribute a "mite'' towards the solu- 

 tion of some geographical phenomena. 



This deposite, consisting wholly of coarse gravel, is on 

 the east side of the great canal cut through the glazed slate 

 rock for the sloop lock, two hundred feet west of my house 

 at the Old-Bank Place, near the 'north boundary of the 

 city of Troy. It is necessary to state that the canal com- 

 missioners have directed an artificial bay to be formed here ; 

 wherein the branches of the great western canal which first 

 meet the waters of the Hudson are to terminate, into which 

 sloops are to enter by the aforesaid lock. The lock is al- 

 ready erected about half across the river, from the western 

 shore. It being unfinished in the eastern half of the river, 

 the water is pressed with great force against the east bank. 



I need not mention that the uncommon and long continu- 

 ed severity of the past season has formed the ice of the Hud- 

 son of uncommon thickness. It broke up suddenly here, 

 and moved down on Monday the 4th, not with great veloci- 

 ty, but with a degree of force which seemed to threaten even 

 the shores of solid rock. Pressing against the little rock 

 promontory across which the aforesaid canal is cut, cakes of 

 ice shot over, and soon filled the canal. Other cakes press- 

 ing against the bottom of these, crowded them up to a con- 

 siderable height above the water. At length an enormous 

 ice cake appeared, bearing on its back a great quantity of 

 gravel. This began to press against the heaps of ice al- 

 ready formed, which bore much gravel also. Innumerable 

 other cakes from behind, pressed on by the unconquerable 

 waters of the mighty Hudson, soon forced the largest cake 

 across the eanal, and up the eastern bank, so that its eastern 



