156 KANSAS CITY REVIEW OF SCIENCE. 



Character of Tornado Cloud and Attending Motions. — The tornado 

 cloud is, generally speaking, funnel-shaped, that is to say, it tapers from the top 

 downward, not always in the same degree with every appearance of the cloud, 

 but the lower end of it (the part nearest the earth) is invariably the smallest. 

 Whatever the inclination of the major axis of the cloud to the perpendicular, 

 the lower end is the narrowest and nearest the earth. As seen in different posi- 

 tions and stages of development by various observers, located differently, the tor- 

 nado cloud has been called: "balloon-shaped"; "basket-shaped"; "egg- 

 shaped"; "trailing on the ground like the tail of an enormous kite"; of " bulb- 

 ous form"; "like an elephant's trunk," etc., etc. In the majority of instances 

 however, observers describe the cloud as appearing like an upright funnel. When 

 the tip end of the cloud reaches the earth, the violence of its whirl creates a powerful 

 suction over a small portion of the surface and immediately thereupon a peculiarly 

 formed cloud of dust, and finely divided debris, around which there plays small 

 gatherings of condensed vapor, is formed. To all appearances now, the tornado 

 cloud has two heads, one on the surface of the earth and the other in the sky, 

 the bodies of each joining in mid-air and tapering both ways with the smallest 

 diameter at their junction. In other words, the cloud now assumes the shape of 

 an hour-glass and the lower portion, or that assuming the form of an inverted 

 funnel, displays an extraordinary violence. The extreme fury of the tremendous 

 power of the tornado cloud is now experienced and nothing is able to stay the 

 force of its awful march. This last and most fatal form of the tornado cloud is 

 fortunately not a constant feature of the storm. The tornado cloud is constantly 

 changing from the hour-glass form to that of the upright funnel or some other in- 

 termediate shape previously referred to. 



The various gradations of form, not any of which however, affect the stereo- 

 typed relation between the size of top and bottom, number some twenty-five or 

 thirty, so far as I have been able to gather information upon this point. These 

 variations of form are quite important in a critical study of the tornado. They 

 depend upon the peculiar movements of the whirling currents of air within and 

 about the cloud vortex, the direction of the currents being outlined to the eye by 

 the singular disposition of the rapidly condensing masses of vapor. The charac- 

 teristic motions of the tornado cloud number four and are described as follows : 



No. I. is called the whirling ox gyratory motion of the tornado cloud, which is 

 invariably from right to left or against the course of the sun. From the peculiar 

 character of the formation of the tornado cloud, this motion is in all probability 

 the first evidence of the existence of the cloud and should therefore be placed first 

 in order of consideration. Of all other motions, this is attended with the greatest 

 violence and its velocity of movement is far in excess of any one of the others. 

 This gyratory motion forms what is termed the vortex of the tornado cloud, within 

 which the velocity of the centripetal currents of air is almost beyond conception. 

 Many efforts have been made, but most of them altogether fruitless, to estimate 

 the rate of progress of these currents and velocities ranging from loo to 800 and 

 even 1,000 miles per hour, have been approximated. The two latter are the ex- 



