56 PHILOSOPHY OF STORMS. 



ally increase in size in their upward motion, by the finer 

 particles of condensed vapor constantly overtaking them in 

 their course, and uniting with them, until, by their increas- 

 ing size, and the diminishing force of the air, from its di- 

 minishing density, they would stop their upward motion, 

 and be thrown off at the sides of the vortex, as explained 

 before. 



It is worthy of remark, also, that the suddenness with 

 which " the cloud gathered blackness, and spread in every 

 direction, till it enveloped the whole heavens," is easily and 

 naturally accounted for by the outward motion of the vor- 

 tex above, as explained in a preceding part of this section, 

 Even the direction in which the spout leaned, from the 

 wind, could have been predicted from the theory. 



84. In the Edinburgh Philosophical Journal, volumes 5 

 and 6, are given descriptions and plates of water spouts, 

 which appear to me almost to demonstrate, of themselves, 

 the theory here advanced. Several of these spouts were 

 attended with rain, at the distance of about a quarter of a 

 mile from the spout, and they all began to descend from the 

 cloud in the form of an inverted cone, that gradually pro- 

 ceeded downwards to meet a smokelike appearance, which 

 rose from the surface of the water to meet it. 



This cone was black at first, but, towards the end, it be- 

 gan to appear like a hollow canal ; the sea water could, 

 even while it was entirely black,- be seen very distinctly 

 flying up along the middle of it, as smoke does up a chim- 

 ney, with great swiftness ; and the wind, in all instances 

 where mentioned, blew towards the spout below. These 

 phenomena, with the exception of the hollow canal, have 

 already been explained. 



In the fourth volume of the Abridgment of the Transac- 

 tions of the Royal Society of London, a description of many 

 other spouts is given, attended with circumstances similar 

 to those already described. One of these occurred in Eng- 



