VOL. XLII.] PHILOSOPHICAL TRANSACTIONS. 5g7 



of one of them, quite round it, and found 32 fathom water, and the height 

 above the surface but 10 yards; another was 28 fathom under, and the perpen- 

 dicular height but 9 yards above the water. 



Capt. M. accounts for the aggregation of such large bodies of ice in this 

 manner: all along the coasts of Davis's-straits, both sides of Baffin's-bay, 

 Hudson's-straits, Anticosh, or Labradore, the land is very high and bold, and 

 100 fathoms, or more, close to the shore. These shores have many inlets or 

 fuirSj, the cavities of which are filled up with ice and snow, by the almost per- 

 petual winters there, and frozen to the ground, increasing for 4, 5, or ^ years, 

 till a kind of deluge or land-flood, which commonly happens in that space of 

 time throughout those parts, breaks them loose, and launches them into the 

 straits or ocean, where they are driven about by the variable winds and currents 

 in the months of June, July, and August, rather increasing than diminishing 

 in bulk, being surrounded, except in 4 or 5 points of the compass, with smaller 

 ice for many hundred leagues, and land covered all the year with snow, the 

 weather being extremely cold, for the most part, in those summer months. 

 The smaller ice that almost fills the straits and bays, and covers many leagues 

 out into the ocean along the coast, is from 4 to JO fathom thick, and chills 

 the air to that degree, that there is a constant increase to the large isles by the 

 sea's washing against them, and the perpetual wet fogs, like small rain, freez- 

 ing as they settle on the ice; and their being so deeply immersed under water 

 and such a small part above, prevents the winds having much power to move 

 them; for though it blows from the north-west quarter near Q months in 12 

 and consequently those isles are driven towards a warmer climate, yet the pro- 

 gressive motion is so slow, that it must take up many years before they can get 

 5 or 6 hundred leagues to the southward ; probably some hundreds of years are 

 required; for they cannot well dissolve before they come between the 50th and 

 40th degree of latitude, where the heat of the sun consuming the upper parts, 

 they lighten and waste in time; yet there is a perpetual supply from the northern 

 parts. 



Observations of the longitude, latitude, and the declination of the magnetic needle, 

 at Prince of Waleis Fort, Churchill River. 



Having observed the apparent time of an emersion of Jupiter's first satellite 

 at Fort Churchill, on Saturday the 20th of March last 1741-2, at u'' 55"' 50'. 



And as the same emersion happened at London, by Mr. Pound's tables, 

 compared with some emersions actually observed in England near the same, at 



is'' 15" lO'. ;(...(■ ; , 



Hence the hoary difference of meridians between Fort Churchill and Londoa« 

 comes out &" IQ'" 20^ 



V 



