[ 272 ] 
as might have been expected, had gravitation to the 
earth been the only principle concerned j but it de- 
fended no lower than to a certain depth in the atmo- 
fphere, after which it feems to have rifen again, and 
made a conliderable progrefs in the higher regions ; 
contrary to Dr. Halley’s opinion about fuch meteors, 
which, he believed, aftually came to the ground *. 
And here I will venture to affirm, that, after perufing 
all the accounts I could find of thefe phenomena, I 
have met with no well-vouched inftance of fuch an 
event : nor is it to be imagined but that, conlidering 
the frequency of fuch appearances, if thefe meteors 
had really fallen, there mult have been long ago fo 
flrong evidence of the fa£t, as to leave no room to 
doubt of it at prefent. Their defcent, under the ho- 
rizon, is fufficient to make the common obfervers 
believe they fee them come to the ground, whilft an 
explofion, high up in the air, coming late to their 
ears, paffes for the craffiing noife of the fall. Not that 
I call in queflion the poffibility of their touching the 
earth ; which they are likely to do as often as they 
move perpendicularly towards it, and not in that ob- 
lique direction fo often mentioned, and by which 
means, it fhould feem, they are conflantly reflected 
by our atmofphere. All that I would conclude is, that 
hitherto we have had no certain proof of their fall ; 
and it is to be hoped, that their motions, like thofe 
of the comets, have been fo regulated at firft by 
a governing Power, that we have nothing to appre- 
hend from their aberration. Unlefs we fhould ima- 
gine, that the perpendicular defcent and burffing of 
* Videloc. cit. 
one 
