AMERICAN GEOLOGISTS AND NATURALISTS. 53 



Stream, here not far from four hundred and fifty miles wide. From 

 this point to the locahty in which the fragments were seen, its course 

 would be about south 81° west, and the distance one thousand four 

 hundred and seventy miles. Assuming that the eddy current and 

 heave of the sea combined, were equal to impelling it westward at 

 the rate of three quarters of a mile an hour, it would require about 

 eighty days to transport it to the locality in question. But as the 

 wind, although acting upon it generally from the eastward, cannot be 

 supposed to have done so constantly, it might be a considerably 

 longer time in performing the voyage. 



Mr. Couthouy exhibited a chart of the Atlantic, with the assumed 

 track of the iceberg met by him, marked upon it, and pointed out 

 that its drift westward must have been at least as great as he had 

 there represented ; since it could not, owing to the trend of the coast 

 of Newfoundland, have entered the Gulf to the westward of the 

 point designated, but on the contrary was likely to have done so fur- 

 ther eastward. Moreover, as it could by no possibility have reached 

 the spot where he fell in with it, without having been driven across 

 the Gulf Stream into the westerly eddy, it was obvious that unless 

 the heave southwestward by the northeasterly wind and swell were 

 admitted, it must have been for a much longer period in the Stream, 

 and finally emerged to the southward of it, at a point much further 

 south and east than he had assumed in his calculation of its course. 



That a mass of ice so considerable should remain after so long a 

 sojourn amid the warm waters of the Stream, would not, he observed, 

 appear surprising, when the enormous magnitude of some of the 

 masses that have been encountered by voyagers in these seas was 

 taken into account ; together with the fact that they produce by their 

 dissolution, carry about with them, and occasion to a great distance 

 around them, a very material decrease of temperature, both in the 

 air and ocean, which tends to render the operation a much more 

 gradual one than we might at the first glance imagine. From the 

 record of a journal kept by Francis D Mason, Esq., in June, 1810, 

 on a passage from New York to Halifax, N. S., and published in 

 Blunt' s American Coast Pilot, edit. 1827, it appears that the water 

 at seven miles from some icebergs, was from 12° to 15° below the 

 average temperature Avhere it was not affected by the presence of 

 such bodies. One of these islands is represented as having been one 

 hundred and fifty feet in height, and a mile in extent. It was easy 

 to conceive of masses like this, resisting the action of air and water 

 for a much longer period than would sufiice to place the berg, whose 

 course has just been described, so far from the point of its northern 

 entrance into the Gulf Stream. 



The last iceberg of which Mr. C. was prepared to speak from per- 

 sonal observation, was encountered by him on the 4th of March, 

 1841, in the Pacific ocean, during a passage from the Hawaiian 

 islands to Boston. It was of great magnitude. Its height could not 

 have been less than two hundred and eighty or three hundred feet. 



