374 
TRAVELS IN 
on each other, formhig natural chambers, arches, colonnades^ 
and Stonehenges ^ to "the magnitude of which, that on Salifbury 
Plain would appear but as a cottage by the fide of that city's 
great cathedral ; all of thefe fo wafted, and corroded, and 
cavernous, the fl^eletons only of what they once were, ftruck 
the mind with the fame kind of melancholy awe, that the con- 
templation of the remains of ancient grandeur generally in- 
fpires. Waiting in the midft of thefe antique ruins, the mind 
was in vain bufied in trying to form fome eftimation of the 
meafure of time that had palTed away in efFe£ting the general 
depreffion of the mountain, and equally vain was it to attempt 
a calculation, in how many ages yet unborn, the ftupendous 
mafles, of at leaft a thoufand feet high, of folid rock, would 
dilTolve, and " leave not a rack behind." 
It could be at no lofs, however, to comprehend, whence 
proceeded the fandy plains that ftretched along the weftern coaft 
of this country, to a diftance yet untravelled. This range of 
mountains alone, taken at two hundred miles in length, five 
miles in width, and the general depreffion at a hundred feet 
only, would have fupplied materials to cover uniformly to the 
depth of three feet, a plain of thirty-three thoufand fquare 
miles. A farther idea fuggefted itfelf, that all the fand of the 
fea fhores probably owed its origin to the remains of worn- 
down mountains, fcattered by the winds, and borne down by 
torrents into the " bofom of the deep," and thence thrown 
back upon its fhores. This theory feems to be eftablifhed by 
fa£ts. In Africa the whole coaft is fand, from the Cape of 
Good 
