METEOROLOGICAL DISCOVERIES. 199 



much light and corrected many wrong impressions, but they choose rather to 

 ignore the light than t > seek it and profit by it. 



To-day, meteorology is still taught, or better, attempted to be taught, on the 

 old plan; might as well undertake to teach pupils geography with the books and 

 light of the fourteenth century as to attempt, to-day, to teach them meteorology 

 without the Weather-Map. The reader may think I am too eulogistic and simply 

 trying to " write up '' something beyond its value. All I have to say to such as 

 may think so, is, to study the map thoroughly and note its revelations day by 

 day. Before taking the map, however, let one ask himself what he knows about 

 the weather. After a careful study of the map for a year or two let him compare 

 notes with what he then knows, and what he knew before. If the map has not 

 revealed his former ignorance then he has not been a good observer and made the 

 best use of his time. The great important thing the map reveals to us is that 

 the areas of high and low barometer move across the country on general lines 

 from the west towards the east. " Low," or low barometer is the governing 

 factor, and may be likened unto the valley, while "High" represents the hill. 

 The currents of atmosphere are from the " High" to the "Low." The cause of 

 low-barometer we ascribe to concentrated heat. The great property of heat is to 

 expand or rarify the particles of matter with which it comes in contact. The 

 air at the point " Low " is rarified : the result of this is the inrushing of cold cur- 

 rents to supply the place of this air so rarified and makes what we call the wind. 

 So the movement of atmosphere is always towards " Low." The great reservoir 

 of air is the area of " High " or high-barometer. The air rushes along the surface 

 of the earth, from all points of the compass, from "High" towards "Low"; 

 here, by the force of heat, it ascends till it reaches the upper stratum of the atmos- 

 phere. From here, judging from the upper movements of the light clouds, the 

 direction is outward from the centre " Low " towards the " High," or better, the 

 upper part of the column " High " to supply the withdrawing of the atmosphere 

 from the bottom of the column " High." 



The surface current, or what we term the wind, is, on general lines, from 

 " High " to " Low" — the upper or atmospheric currents from " Low" to " High." 

 At the surface of the earth from the cold to the hot, at the surface of the atmos- 

 phere from the hot to the cold — the vacuums as it were being reversed. On the 

 surface of the earth " High" is the highest, "Low " ihe lowest, while at the top, 

 or upper stratum of atmosphere the highest point would seem to be at " Low " 

 — "Low" the highest, "High" the lowest. When we speak of the movement 

 of the atmosphere, its movement along the surface of the earth, or its terrestrial 

 movement is to be understood. The movement is from the "High" to the 

 " Low." This being the case if " Low " is on a high hne of latitude, say at 50° 

 north, or beyond, we will have south winds ; and south winds are warm ; that is, 

 winds from the far south; the further they are from the south, and the further 

 they travel over the country, the warmer they become. That is why it is, in 

 summer time, often warmer along the northern line of the United States than at 

 the south. But although these areas of Low-barometer travel from the west 



