[ "5 3 



. IT having been proved, from what hath been already urged, 

 as well as by the preceding experiments of Dr. Higgins, that the 

 floating ice, which is obferved both in high fouthern and northern 

 latitudes, cannot be probably formed from fea-water, it may be 

 thought incumbent upon me to Chew how filch quantities can be 

 lupplied from fprings, rain, or frozen fnow. 



The rivers which are always found at certain intervals in 

 any large tract of land undoubtedly fupply confiderable part of 

 fuch ice ; but there are not wanting other fources from which 

 thefe floating maiTes may be produced. 



The larger and higher ice iflands y I conceive to be chiefly 

 formed on fhore, after which they are undermined by the rills and 

 melted fnow, during the fummer, of which we have- an accurate 

 account in the late voyage towards the North Pole*. 



Others 



7 Mr. Wales obferves, that in the iflands of ice, near Georgia Auftralis 

 and Sandwich-land, there are ftrata of dirty fcej which irrefragably proves 

 their having been formed on the land. Remarks on Dr. Former's Ac- 

 count, &c. Svg. London, 1778, p. 106.. 



With regard to the formation of Ice-iflands, fee likewile Captain 

 Cook's Voyage, Vol. II. p. 213 and 240, who conceives them to arife 

 from congealed fnow and fleet in the vallies. Captain Cook alfo fup- 

 pofes, that the ice-cliffs, at the end of thefe vallies, often project a great 

 way into the fea, when they are flickered from the violence of the 

 wind, p. 242. 



z " Large pieces frequently break off from the Ice-bergs, and fall 

 " with great ncife into the water: we obferved one piece which had 

 " floated out into the bay, and grounded in twenty-four fathoms; it was, 

 ft fifty feet high above the mrface of the water, and of the fame beauti- 

 " ful colour as the Ice-berg." p. 70- 



I have likewife been favoured with the following account of Ice 

 iflands on the coafh of Labradore, from Lieutenant John Cartwright, 

 ©f the Royal Navy, to whom I have not only this obligation. [See the_ 

 Probability of reaching the North Pole, p. 5.] 



* " Dear 



