112 TRANSACl'IONS OF THE ILLINOIS 



South Africa. This is the position of these periodical barometers from 

 the first of April to the first of October ; but from the first of October to 

 the first of April, the relative position of these high and low barome- 

 ters is reversed ; that is, the high barometer is in Central Asia, and the 

 low in South Africa. Now, according to the principles advanced, there 

 should be from April to October a wind blowing from South Africa to 

 Central Asia, and from October to April from Central Asia to Africa. 



If you examine your books, you will find that in Hindostan and on 

 the Indian ocean, intermediate between these two points, the southwest 

 monsoon blows from April to October, and the northwest from October 

 to April. You again have before you an illustration of the laws and 

 causes of winds, as exemplified in the northeast and southwest monsoons. 



The same principle, when applied to either permanent, periodical, 

 temporary or variable winds, is found to be universally true. By taking 

 the daily observations of the Signal Service Bureau, you can verify the 

 principle for every day in the year. 



The cause of winds and the laws of their movements are so plain and 

 simple that a child of ordinary capacity, still on the sunny side of the 

 "teens," can not only comprehend them, but apply them so as to show 

 the direction of the wind from any given statement of the readings of the 

 barometer. 



All fair and candid minds, not preoccupied by the phantastic hypo- 

 theses of the dead past, will admit that the exegesis of the winds here given 

 is so plain, simple and lucid, as to be almost, if not quite, a self-evident 

 truth. All I ask is a rigid scrutiny of facts and a vigorous test of its 

 principles ; and then I will have no fear that the public verdict will not 

 be, the barotneter tells its all about the winds. 



I have already stated that the barometer has not taught us half that 

 it is capable of doing. I will not trespass upon your patience by proving 

 what I hold to be tl'te exciting cause of high and low atmospheric pressure, 

 or high and low barometers, as they are generally called. I am convinced 

 the cause is electricity ; and therefore that the descending current of air 

 over an area of high barometer, and the ascending current over an area 

 of low barometer are electric currents. Balfour Stewart said something 

 to this effect, that the test of a theory is not so much by the facts it ex- 

 plains, as by the new facts it discovers by suggesting them. 



In my investigations, I make it a rule never to accept any theory as 

 true, whether projected by myself or others, until it has stood the test, 

 not only of the whole class of facts it was intended to explain, but all the 

 facts that necessarily appear and fall into line if the theory be true. 



When I first commenced the study of high and low barometers, I 

 had a notion that a high and low barometer had a natural tendency to 

 coalesce and obliterate each other. Comparing this notion with the idea 

 tliat they were electric currents, I clearly saw that the two ideas were 

 incompatible, since the law of reciprocal action — as discovered by Am- 

 jjere — between parallel electric currents, is, that if they flow in the same 

 direction they attract, but if in opposite directions they repel each other. 

 It hence follows that either high and low barometers do not coalesce, 



