STATE HORTICULTURAL SOCIETY. ^^ 



electric waves that we must look for the laws and explanation of the 

 formation of clouds, and consefiucntly of rainstorms. 



The fore-casts of the weather are made upon the state of atmos- 

 pheric pressure as indicated by the barometer. When the barometer is 

 rising at our locality or west of us, we confidently ])redict clear weather. 

 On the contrary when it is falling, we as confidently predict the apj)roach 

 of cloudy weather, and a storm whose violence we estimate by the ra- 

 pidity and extent tliat the barometer falls. 



We are not now speaking of the two daily risings and fallings of the 

 barometer which have a fi.xed position in relation to the Sun, the former 

 occurring regularly with but little variation at nine o'clock a. m., and 

 about ten o'clock p. M., the latter about four o'clock a. .\i., and three 

 p. -M.; but we are speaking of those secular and irregular variations in 

 pressure which occur with more or less frequency and at intervals of 

 longer or shorter duration, and whose wave-like motion is from west to 

 east at the rate of from eighteen to thirty-six miles per hour. These 

 waves carry beneath them the phenomenon called low-pressure. The 

 wave is dual to correspond with the two electric poles, and can appro- 

 priately be represented by an hour-glass. The positive wave of the 

 upper atmosphere, being an inverted cone, is met by a counter cone on 

 the surface of the Earth. They have no great breadth from east to 

 west, but sometimes have great length from north to south. They 

 move side-ways toward the east, their line being frequently straight, but 

 generally it is curved with the convex side toward the east. But our 

 attention must be fixed upon the apexes of these cones, for there the 

 phenomena are taking place which solve our problem, namely: the most 

 intense action and reaction. 



We have seen that these invisible cones or rolling waves, — revealed 

 to us only by the barometer, — are the opposite poles of electricity ; and 

 between opposite poles in such a position, there is always a reciprocal 

 interchange of their respective electricities to relieve their tension. The 

 atmosphere, — as already stated, — is a nonconductor of electricity, and 

 as electricity cannot pass without being conducted or conveyed, there- 

 fore some medium must be found to bring the opposite electricities 

 together. 



In speaking of the apparent general eastward movement of the at- 

 mosphere, it was shown to be really only an electric current conveyed 

 by attenuated cirrus clouds and other invisible aqueous vapors. The 

 case before us of conical electric waves rolling eastward, one on the sur- 

 face of the Earth and the other opposite but inverted in the clouds, 

 mutually neutralizing each other by one discharging in the other, is only 

 another aspect of the same phenomenon, namel), aqueous vapor i on- 

 veying electricity. 



For illustration of these natural phenomena we must here refer to 

 similar ones which we can reproduce on a small scale in our laboratories. 

 The electric matihine has attached to it a brass cylinder called the con- 



