of the Earth's Atmosphere. 283 



period and a 14-year period, it is evident that the summation 

 will destroy all evidences of periodicity and synchronism in 

 the minor fluctuations. The long periods may survive with a 

 feeble amplitude, while the short periods will certainly vanish. 

 It is a misnomer to speak of these irregular oscillations as 

 periods, and it is a non sequitur of analysis to assume that 

 synchronism depends upon periodicity. If the irregularities 

 in the variations of the solar and the terrestrial phenomena 

 match each other in the time-sequences, this is a better proof 

 of synchronism in physical causes and effects than could be 

 obtained by employing a definite period having wide ampli- 

 tudes of oscillation. 



Inversion effects. 



Besides the impropriety of forcing the observed departures 

 of different phenomena into mean periods which do not exist 

 in nature, there is a failure to recognize the fact that the same 

 external or general cause, as an increase in the solar radiation 

 energy, may produce inverted effects within the earth's atmos- 

 phere when different localities are compared together. Since 

 the total weight of the earth's atmosphere remains fixed, it is 

 obvious that the pressures of the atmosphere can be distributed 

 in diverse manners only by balancing an excess in one region 

 by a defect in another region. It has been found that the 

 pressures of the atmosphere of the earth as a whole vary in 

 such a manner that the years of annual excess in the eastern 

 hemisphere are compensated by simultaneous deficiencies in 

 the western hemisphere, the variations following the sequence 

 of the solar prominences. Since the sum of the moments of 

 inertia for the whole earth's atmosphere must be equal, in 

 order to maintain the period of the earth's rotation on its axis 

 a constant, it follows that the circulation of the atmosphere 

 adjusts itself automatically under the action of the force of 

 gravitation to certain velocities appropriate to the latitude away 

 from the equator, and the height above the earth's surface. 

 This complex process is only partially understood as yet, but 

 it is evident that along with the readjustment of the circula- 

 tion there is a redistribution of the terrestrial temperatures in 

 latitude and in longitude. Thus, it has been found that the 

 year of excess of temperature in the tropical zone is accom- 

 panied by a defect of temperature in the temperate zones, this 

 being due to the return-cold or polar currents bringing down 

 air from the higher levels to the surface in temperate zones, 

 to compensate for the increase of the upward circulation in 

 the Tropics as caused by the increase in the solar radiation. 

 This general principle has many exceptions in the temperate 



