J20 ESSAYS AND OBSERVATIONS 



terjacent plains and valleys, one may of- 

 ten emerge out of the mift by going up 

 fome neighbourmg hill ; then he will fome- 

 times fee the whole country around, as it 

 were, buried under a vaft deluge ; and 

 nothing but the tops of diftant hills, ap- 

 pearing here and there above the flood j 

 and he will think of diving down again 

 into it with,a kind of horror. 7 he air 

 at that timd, in thefe regions, is very pure, 

 ferene, and agreeable to breathe in. 



During this kind of weather, there 

 is another phasnomenon obfervable. which 

 1 have feen many years ago ; namely, a 

 rainbow formed round one's fhadow in 

 the mift. The French and Spanifh gen-» 

 tlemen who went to Peru, with a view to 

 determine the figure of the earth, having, 

 among many other difficulties, the embar- 

 rafTment of tedious and very frequent fogs 

 to:flruggle with, had often occafion to 

 obferve this phccnomenon. It feemed al- 

 fo worth mentioning here, that any one 

 who has the curiofity may fatisfy himfelf 



concerning it. 



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