148 KANSAS CITY REVIEW OF SCIENCE. 



volving current of air, first appears as a dark cloud of minutely divided particles of 

 water, the result of rapid condensation, of course in the air and therefore above the 

 water. The swift passage of the air in a spirally upward motion over the surface 

 of the water raises it in the form of spray and carries it upward in the centre of 

 the whirling cloud, which then presents the appearance of a densely opaque body 

 and conveys an impression to the eye of the observer, that a huge column of water 

 is ascending in the form of a long spout, widening gradually toward the top. 

 There are instances, however, where the force manifested was sufficient to raise 

 a considerable quantity of water several hundred feet in the air. Waterspouts 

 form during periods of excessive heat, generally in the afternoon and at or 

 near the hottest part of the day. In the temperate zone they only occur during 

 summer months. 



They are of most frequent occurrence in the region of calms between the 

 Tropics, but are not altogether strange sights in the Gulf of Mexico and 

 along the Gulf stream south of parallel 40° N. In regard to motions they possess 

 both a rotary and progressive action, but in neither do they manifest a perma- 

 nency of direction. Waterspouts cannot be considered as altogether harmless for 

 there are instances where vessels have been wrecked by them. 



Hailstorms — Are peculiar atmospheric disturbances which, in regard to the 

 dimensions of their paths, are next to the tornado the most circumscribed of all 

 storms save the whirlwind. They are characterized by a strange cloud formation 

 and a peculiarity of precipitation unlike any other phenomena in the category of 

 storms. The cloud from which the hail falls is basket-shaped with a dark and 

 portentous exterior, a ragged and ominous looking opening at the bottom, and 

 within, a whirling conglomeration of snow-flakes, pellets of snow and ice, partly 

 formed and perfect hailstones, the latter of an almost infinite variety of shapes. 

 The hail cloud forms between the currents of the upper and lower regions of the 

 -atmosphere and moves forward in the plane of these currents, either within or 

 just above the upper limit of the lower atmospheric regions, where it finally dis- 

 appears and the deposition of hail ceases. The path of the storm as indicated by 

 the distribution of the hailstones is at times very narrow, although the range of 

 width is decidedly inconstant, varying from one to fifteen miles. The hailstorm 

 travels quite rapidly, from thirty to fifty miles per hour, and the length of its path 

 is even more variable than the diameter, ranging as it does from ten miles to two- 

 or more hundred. The direction of the course pursued by the storm is always 

 from some point west to some point east. It may be from northwest to southeast 

 or from southwest to northeast. Hailstorms may occur at any time of the day or 

 night, although they are most frequent in the afternoon, just after or near the 

 hottest part of the day. 



They are most prevalent in that region of country embraced between the 

 parallels of 30° and 50° N. South of parallel 30° N. hailstorms are of rare oc- 

 currence at the level of the sea, but at the height of one or two hundred feet they 

 occur more frequently, and in the mountains of British India they are very com- 

 mon, the hai stones being usually of large size. Hailstorms are not necessarily 



