453 



the latter cafe, the banks muft be Jieep, uniform, and of a given de- 

 clivity ; while thofe with gentle inclination, mild fwells, and varying fur- 

 face, could never have been touched by Mr. Playfair'^ inftruraent. 



Though he tells us, (page 1 1 1 ) " the refult of a more minute in- 

 vejiigatien, would be in perfeSt unifon with the general imprejfton of wajle 

 and decay ;" I fhould be glad to accompany his geologift, and to def- 

 cend with him from his Alpine trails, and trace the courfe of any 

 river, from its fource to the fea ; I think I could fliew him, that the 

 places afled on by the river, fince it ~firft ran, were not many, and 

 the quantity of materials carried off, comparitively nothing ; that in feve- 

 ral of thefe places, a bulwark had been formed at the bafe of the 

 fteep, by the ftones and rubble which had fallen down, and that thus 

 further depredations were prevented, of courfe that the progrefs of de- 

 cay is not to be found in the courfes of rivers. 



Perhaps this geologift would not thank me for difpelling his gloomy 

 vifions, 



" Cui fie extorta voluptas, 

 " Et demptus per vim mentis gratiffimus error." 



Should this be the cafe, and his imagination fo habituated to dcf- 

 ponding fpeculations, that the profpeft of ruin and defolation is become 

 a neceffary food to it, I would advife him, as there feems to be 

 little hope of the world's making away with itfelf, to look for its de- 

 ftruftion from external caufes, and to calculate with Swift's wife iflan- 

 ders. 



How foon the earth, by its daily approach to the fun, is likely to 

 be abforbed by it ? 



How foon the fun itfelf will be incrufted by its own cfHuvia, fo as 

 to ceafe to give light and heat to the uuiverfe, and 



How foon we 'nay expeft it will be confumed and annihilated, by 

 the perpetual expenditure of its rays, without nutrimcat? 



TO' 



