And in her silver girdle binds her isles;
Onward, where NIGER'S dusky Naiad laves
A thousand kingdoms with prolific waves,
Or leads o'er golden sands her threefold train
540 In steamy channels to the fervid main,
While swarthy nations croud the sultry coast,
Drink the fresh breeze, and hail the floating Frost,
NYMPHS! veil'd in mist, the melting treasures steer,
And cool with arctic snows the tropic year.
545 So from the burning Line by Monsoons driven
Clouds sail in squadrons o'er the darken'd heaven;
Wide wastes of sand the gelid gales pervade,
And ocean cools beneath the moving shade.


[_On ice-built isles_. l. 529. There are many reasons to believe from
the accounts of travellers and navigators, that the islands of ice in
the higher northern latitudes as well as the Glaciers on the Alps
continue perpetually to increase in bulk. At certain times in the ice-
mountains of Switzerland there happen cracks which have shewn the great
thickness of the ice, as some of these cracks have measured three or
four hundred ells deep. The great islands of ice in the northern seas
near Hudson's bay have been observed to have been immersed above one
hundred fathoms beneath the surface of the sea, and to have risen a
fifth or sixth part above the surface, and to have measured between
three and four miles in circumference. Phil. Trans. No. 465. Sect. 2.

Dr. Lister endeavoured to shew that the ice of sea-water contains some
salt and perhaps less air than common ice, and that it is therefore much
more difficult of solution; whence he accounts for the perpetual and