IVca/ficr, U'dtcr and Disease. '3 



Many more illustrations can be given of ecjual rises of tem- 

 perature in less than sixteen hours at Denver. 



It will be realized from these figures that there is need for 

 unusual powers of resistance at intervals at least. 



How much a storm may include in its embrace at any one 

 station in its ])rogress, and how many indixiduals it may affect, 

 can be realized from T. Russel's statement in "The Kngineer- 

 ing Magazine," December, 1891, as to the "conditions of a 

 cold wave." He says: " A cold wave is a fall in temperature 

 of twenty degrees or more in twenty-four hours, free of diurnal 

 range, and extending over an area of at least 50,000 square 

 miles of country, the temperature somewhere in the area going 

 at least as low as .36°." In one of the greatest cold waves in 

 recent years, that of February 17, 1883, the temperature at 7 

 A. M. was twenty degrees lower than at the same hour on the 

 day preceding throughout an area of 1,065,000 square miles, 

 extending from I^ake Superior and Georgian Bay on the north 

 to the Rio Grande on the south, and from Kansas City to Cin- 

 cinnati. Inside of the area of twenty degrees fall there was 

 an area of thirty degree fall of 640,000 square miles ; inside of 

 the area of thirty degree fall there was an area of 187,000 

 square miles; inside of the forty degree fall there was 31,000 

 square miles of fifty degree fall, and inside of the fifty degree 

 fall a fall of sixty degrees at Keokuk, Iowa, the center of the 

 cold wave. In ten years there have been two cases with the 

 falls at the center greater than sixty degrees; the greatest 

 being sixty-three degrees at Moorehead, Minn. There have 

 been sixteen cases with the greatest fall between fifty and 

 sixty degrees ; sevent5'-seven between forty and fifty degrees; 

 284 between thirty and forty degrees and 278 betw^een twenty 

 and thirty degrees." It is a fascinating story of the great 

 upper ocean of the atmosphere. Add to it a calculation of 

 the weight of this air moving in its fury over a million and 

 more of square miles, and we need not wonder at the myths of 

 old, which put " Vulcan forging thunder bolts, Jupiter hurl- 

 ing them at his enemies, and Eolus directing in the cave of 

 the winds." Or the later conceptions of theological origin, 

 which saw demons and witches riding or originating storms 

 for sinister purposes. 



Another component of weather is the atmosi)heric pressure — 

 which, at sea-level, is nearly fifteen pounds to the square inch. 



