378 Dr. Gray's Account of the Earthquake 
infinite velocity ; consequently its effects are limited in their 
extent, and it is instantaneous in its operation. Whereas 
earthquakes have, more than once, extended their effects over 
immense portions of the globe ; and they appear to move 
(sometimes at least) with a degree of slowness of which we 
cannot suppose the electric fluid capable, without supposing it 
thereby so far divested of its destructive power, as to be inca- 
pable of producing what is truly considered as the most dread- 
ful of all natural phenomena.* 
The foregoing reflections are offered as naturally arising 
from the consideration of the account here given, and by no 
means as taking either side of the great question, whether 
earthquakes are to be considered as terrestrial or as aerial 
phenomena. A question which appears to me to be involved 
in the greatest obscurity ; and this obscurity seems to arise, 
not so much from a waht of arguments on either side, as from 
the arguments on both sides being so many, and so strong, 
that the mind hesitates less which side to choose, than which 
to reject. For as, on the one hand, there are many circum- 
stances attending on earthquakes, (particularly their frequent 
recurrence, in many parts of the world, in the same tract,) on 
which it is impossible to reflect, and not feel disposed to be- 
lieve their cause situated in the earth ; so, on the other hand, 
it seems equally impossible to reflect on the unusual atmo- 
* Of the slowness here spoken of, the earthquake described in the foregoing page? 
affords sufficient example, particularly in its progress from Kenilworth to Wollaton; 
(see page 374;) but, in the account of an earthquake felt near Oxford, June 19, 1665, 
it is said, that “ Dr. Holder, F. R. S. who was then at Blechington, took notice that it 
“ was observed by those in the further part of the garden, some very discernible time 
•f before it was observed by those in the house, creeping forward from the one place t* 
“ the other.” See Phil. Trans. Vol. I. page 169. 
