202 KANSAS CITY REVIEW OF SCIENCE. 



Whether " Low " will produce rain or snow depends upon its latitude as well as 

 upon the season and the latitude of the section of the country over which it 

 passes. To enumerate all the changes of " High" and " Low," and to show the 

 effects which they have upon the climate of the country would fill volumes. As 

 the changes are infinite the variety must be in proportion ; only by the Weather- 

 Map can we be aware of these changes and study their effects. Until we had 

 this wonderful map we had little or no conception of the meteorological phenom- 

 ena of the world. For example the tornado. The old "physical geography" 

 system had various names for this violent phenomenon, such a.?, cyclone, hurricane, 

 and tornado, and undertook to draw a line between them, giving certain charac- 

 teristics to one which it did not give to the other. The map reveals the fact that 

 they are all one and the same, and that they proceed from "Low," and under 

 certain conditions of "Low" the different localities of the earth will have the 

 severe storm which may be called by either of these names. The mere descrip- 

 tion of one of these storms might fill volumes, but from them we gather little or 

 no knowledge of their cause, we only learn of the effect, but follow up the 

 Weather-Map and their cause as well as their effect will be fully revealed. 

 The tornado comes from " Low " and always takes place in the track of this 

 factor, which for short we term " Low." One " Low " passing over the country 

 will not produce the effect, any more than a little fire would in a short time heat 

 a large room. We must have a succession of " Lows " on a high line, or rela- 

 tively high line, in order to obtain, through the south winds, the necessary 

 amount of heat. Every " Low," even high " Low," will not produce a tornado, 

 if it did we would not only have one every day but every hour of the day all over 

 the country. 



The map reveals the fact that the violent wind-storm we call Tornado or 

 Cyclone, when it occurs will always be in the track of " Low" and generally at 

 E B an acute angle thereto, say 



an angle of about 15° or 20° 



to the line of the track of 



" Low." Let the centre of 



A- ^/^ "Low" one morning be at 



A; the next morning at B. 

 The tornado will take place 

 C^ on the line C D or E D, or- 



even between the angle C D E, in the track of " Low." 



Volumes have been written upon the subject of Climatology, but the subject 

 will never be understood until we seek the proper information from the Weath- 

 er-Map. By this map we can understand the Climatology of the United States 

 as never before, and when the rest of the world is as well supplied in this respect 

 as the United States we will then and not till then understand the full climatology 

 of the world. The climate of the eastern and western coasts of continents is 

 quite different. Under the old system, which is still present with us, this is all 

 said to be due to the warm currents of the ocean. But the "Weather-Map" 



