WIND ann WATER-SPOUTS, &c. 345 
wards; and it is this alone that does prevent it. By a 
failure in this, a defcent once begun, the confequences 
cannot be prevented: The heavy quantity above will con- 
tinue to defcend till all the upper cold regions are exone- 
rated to many hundreds of miles round; and all their 
contents fhifted into the place of the rarified and lighter 
air below. 
Such are my ideas of the caufes and operations of a 
- hurricane in thofe climates. I have only to add here, that 
the rains in thefe violent ftorms are, as J think, a ftrong 
confirmation of the doctrine of defcent; as they are in that 
kind of hurricane called by failors the Ox’s Eye, on the 
coaftof Guinea; and the like happens under various names 
in different parts of our globe. Even the wind in our 
thunder-gufts is from defcent ; the air in the cloud being 
rendered denfe and weighty, defcends, and flows in the di- 
rection of the wind of the time, and with the more vio- 
lence, by the warm air at the furface giving way to it. 
Thefe are fometimes ftrong, but feldom attended with 
danger or damage. 
What obje€tions may be raifed againft thefe opinions, 
fhall be candidly attended to; in the mean time there is 
one objection that muft be obviated, the argument being 
fomewhat interefted in it. It is as follows. 
Having exprefled my opinion that hurricanes and tor= 
nados or wind {pouts have the fame general nature, while 
we fee a great difparity in their magnitude and procedure; 
fome explanation feems neceflary to prevent miftakes ; I 
think a little confideration of the place, climate, and cir- 
cumftances may remove the difficulty. 
The earth is an oblate fpheroid, its diameter many miles 
greater at the equator than at the poles, caufed by its di- | 
urnal centrifugal force. If this then has fo great an effect 
on terraqueous matter, it cannot have lefs on our air, but 
if any difference, rather more; efpecially if we confider, 
that the atmofphere makes a larger diameter, and yet re= 
volves: 
