Water S2)outs, 259 



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seemed to be like all the others in sight at the time,) can go in con- 

 firmation of a general theory, it inclines me to the beliel'of that part 

 of Dr. Franklin's hypothesis, which supposes itto be a body of warm 

 air rising from the surface of the ocean to the upper and cooler re- 

 gion, where its moisture begins to be condensed into thick vapor by 

 the cold, thus causing the spout to become first visible at its upper 

 end. As the vapors continue to ascend, hy constant addition they 

 become denser, and consequently their centrifugal force greater, until 

 being risen above the concentrating currents which compose the whirl, 

 they fly off, spread and form the cloud. 



Even Dr. Perkins, in one of his pa[)ers read at the royal society, 

 June 24, 1756, favors this opinion so far as to say, "If spouts ascend, 

 It is to carry up the w^arm rarified air from below, to let down all and 

 any that is colder above." But he adds, " If this be so, they must 

 carry it through the cloud, perhaps far into the higher region, making 

 a wonderful appearance at a convenient distance to observe it, by 

 the swift rise of a body of vapor above the region of the cloud." 

 This is an appearance which I have never observed, nor do I con- 

 ceive it to be at all necessary to the establishment of the fact that the 

 air is carried upward. Such might be the case if the air ascended 

 in a right line, but as I have already stated, it rises with a spiral mo- 

 tion, and as it becomes denser by contact with the colder atmosphere, 

 it of course acquires a greater centrifugal force, wdiich gradually en- 

 larges the upper end of the spout to the trumpet form, until at length 

 it flies off horizontally, thus uniting with, and increasing the cloud, 

 instead of passino- through it. It is possible that when the upper re- 

 gion is much colder than the lower, the condensation of the ascend- 

 ing air may be so great as to cause part of it to fall again through 

 the spout, sometimes in the form of rain, or by a concentration of 

 the drops, even a stream may be poured down, which would in a 

 measure account for the theory of Doctors Lindsay and Perkins, but 

 I could see no evidence of this in any of the spouts near our ship. 

 Some of the officers, however, thought they could see water falling , 

 within the tube, but all admitted the gyratory motion upward, as it. 

 was too distinct for a difference of opinion. 



As to the nature of electricity with water spouts, I must leave that 

 point for others to determine. It is evidently largely combined with 

 them, but whether as the cause, or merely the the consequence of 

 their existence, is a question which you will, no doubt, be able to 

 explain. Spanish navigators of former days, fully believed the 



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