APh iO idi? 



THE OTTAWA NATURALIST. 



Vol- XI. OTTAWA, JUNE, 1897. No. 3. 



"WEATfTER." 



By Otto J. Klotz, 

 President of the Ottawa Literary and Scientific Society . 



(Continued from the May tnimber.) 



The North-West is the breeding ground of our "cold 

 waves." In connection with anti-cyclones there prevail, however, 

 from time to time, especially in the winter months, severe 

 storms of wind, either with or without snow. When accom- 

 panied by snow they arc popularly known as blizzard?. It may 

 be interesting to state in connection with the etymology of this 

 word, that among one of the first to mention the blizzard was 

 Henr}^ Ellis, who made a voyage to Hudson's Bay in the ship 

 '''California" in the year 1746 and wintered near York Factory. 

 In addition to regular storms of low and high barometer, there 

 are other atmospheric disturbances, generally known as local 

 storms, such as hail, thunder and dust storms. From ihe con- 

 centric layers which a hailstone usually presents, when cut in 

 two, one infers a growing process in which the stone passes at 

 least as many times as it has separate layers from a stratum of 

 air having a high temperature to one having a correspondingly- 

 low one. This process would involve a vortex motion, in which 

 the stone is alternately drawn in and thrown out of the vortex 

 and finally, by increasing weight, falls to the earth. It is well 

 known that hailstorms follow a path whose breadth is very nar- 

 row compared with its length. In thunderstorms we have 

 another element — electricity — entering our meteorological phe- 

 nomena. It has been shown that the geological character of the 

 soil has much to do with the frequency of lightning strokes, the 

 proportions being one for a chalk bed, seven for clay, nine for 

 sand, and twenty-two for loam. Oaks are most often and 

 beeches least often struck, and nearly always in the clear or at 

 the forest's edge. The risk ot houses being struck increases 

 with segregation and height, and is five times greater in the 

 country than in the city districts. In very dry countries during 

 the rainless season local whirlwinds occasionally pass over 

 limited sections, the disturbance being similar to that of a feeble 

 tornado. The haze peculiar to the season known as Indian 



