PHILOSOI'IIV OF STOI{M'>. 231 



favorable, we will see some rising above the rest. If \vc watch now un- 

 til one becomes very lofty, and appears to take the lead ol' the rest, its 

 base will no longer remain on the same level, but becomes lower than 

 the bases oflhe other cumuli. The top now ascends until it becomes more 

 lofty than what is denominated the hail-cloudy and as we observe it as- 

 cending higher and higher, we will perceive the base of it descending 

 lower and lower. The base now, instead of being flat as at first, is 

 bulged out below like an udder, projecting one or two hundred yards 

 below the original base. It now begins to spread out at the top, re- 

 sembling the top of a mushroom. We will see the udder continuing to 

 descend lower and lower until at last it reaches to the surface of the 

 earth, assuming the form of an inverted cone, and the whole cloud now 

 looks like the stem and top of a mushroom. If we should be in a fa- 

 vorable situation in relati<m to the cloud it will now appear very deep, 

 and before the udder reaches the earth, we will observe leaves and other 

 light bodies flying up into it, and as the cloud approximates to the earth 

 heavier bodies will ascend, and finally when it strikes the earth it opens 

 upon it with all its fury, carrying up bodies of immense weight, logs, 

 wagons, trees, roofs of barns and houses, kc. with incredible power 

 and velocity. This "besom of destruction" as it travels over the sea 

 produces the Waler-spout^ and on land is the Tornado. 



Although I have spoken of the cloud descending to the surface of 

 the earth, ] have merely described the circumstance as it appears to the 

 eye. The cloud does not sink down as it appears to do, and as is sta- 

 led in vvorks on 3Ieteorology. From what has been said above, the ex- 

 planation of the formation of this inverted cone or udder projecting 

 from the original base of the cloud may be anticipated. As the barom- 

 eter continues to sink under the base of the cloud, the temperature of 

 the air diminishes until it is reduced down to the dew-point in the 

 whole extent of the column from the base of the cloud down to the 

 surface of the earth. At the same time the temperature of the air all 

 around on the outside of the column is, according to what I have as- 

 sumed, ten degrees higher than the dew-point, and consequently so soon 

 as the air outside is driven within the column it is instantly cooled ten 

 degrees, and its excess of gaseous vapor is condensed into cloud at 

 the moment of its ingress. Thus, instead of the base of the cloud sink- 

 ing down and forming the uddei, the latter is caused by the accumula- 

 tion of additional vapor under the base, brought in by ther surrounding 

 air and condensed by the cooling power of the column. 



The levity of these dense clouds and the upward motion of the air 

 are strongly exemplified by the tornado and water-spout. They are al- 



