December 3, 1915] 



SCIENCE 



801 



electricity, metliods of barometric reduction, 

 the meteorology of the isothermal layer, on the 

 laws of evaporation, and a few other subjects to 

 which the author has paid special attention for 

 many years by methods which are often highly 

 original. The book may be regarded as a 

 summation of its author's labors on meteor- 

 ological theory, and records not a few notable 

 advances in meteorological procedure, espe- 

 cially in regard to the reduction of observa- 

 tions. 



To the author of this treatise we already owe 

 the standard system of barometry now used 

 by the Weather Bureau of the United States, 

 an important concatenation of terrestrial me- 

 teorological phenomena and solar changes 

 which, is here presented anew in slightly revised 

 form, a considerable modification of Ferrel's 

 equations for atmospheric movement in storms 

 with an application to tornadoes which has 

 given, for the first time, reliable data for these 

 very intense movements of the air, and some 

 interesting and highly original, though perhaps 

 not entirely conclusive speculations in regard 

 to the causes of the several variations in the 

 electric and magnetic elements. The present 

 work records a further advance in measures 

 of the ionization of the atmosphere which en- 

 able the author to clear up the discrepancy of 

 about 300 per cent, which has hitherto existed 

 between different methods of measuring the 

 dissipation of electricity in the atmosphere. 



The special topic around which all the others 

 cluster is the application of the universally 

 accepted thermodynamic equations to atmos- 

 pheric phenomena. In order to accomplish 

 this, the author is obliged to make the gas 

 coefficient (R) of the usual thermodynamic 

 equations a variable, instead of a constant. It 

 may seem a little risky thus to throw wide open 

 the doors of theory, and to make this funda- 

 mental " constant," so-called (whose value has 

 been accurately determined from laboratory 

 experiments) vary through a wide range, while 

 still retaining the form of the equations whose 

 accuracy rests upon these same laboratory ex- 

 periments. We may ask whether the equations 

 whose accuracy as mathematics is conceded, 

 will continue to be applicable if their basis is 



changed. More than one meteorologist has 

 suggested to the reviewer that Bigelow seems 

 to be trying to make the laws of nature con- 

 form to his equations, with the implication that 

 success in this attempt is somewhat doubtful. 

 It can not be denied that an element of empiri- 

 cism enters into the proposed methods. The 

 author points out correctly that the well-known 

 departure of the atmosphere from adiabatic 

 conditions is inevitable as long as heat and 

 motion (of air currents) are imported into any 

 given volume of air. This is self evident; but 

 will the thermodynamic equations stand up 

 under this extra burden when the effects of 

 wind and radiation, together with several other 

 activities not explicitly named in this " Trea- 

 tise," are included? The author claims that 

 everything checks, but on examination this is 

 found to mean simply that when limited to a 

 narrow round of interlocking operations, the 

 numerical work can be performed consistently. 

 On testing the results by comparison with facts 

 which have not been included in the theory, a 

 few discrepancies and inconsistencies are 

 found. An examination of these in detail 

 would extend this notice far beyond the limits 

 of a review and can not be attempted here. 



It should be distinctly understood that Bige- 

 low's fundamental equation starts with the 

 thermodynamic equation which has been 

 founded on the behavior of a definite volume 

 of a gas or vapor enclosed in hypothetically 

 non-conducting and impervious walls, when 

 only the internal circumstances of pressure, 

 density and temperature are changed; but in 

 the adaptation of this equation to the free 

 atmosphere, other terms are added which 

 represent infringement of this condition by 

 external interference, and still the process is 

 called " thermodynamic." While an enlarge- 

 ment of the boundaries of this science is desir- 

 able, and while perhaps no better way can be 

 found for extending these boundaries than by 

 attending to the experiments which nature 

 performs for us on a gigantic scale, still it 

 must not be forgotten that by this new de- 

 parture we have slipped our moorings and 

 are at sea on an unknown ocean of many vague 

 possibilities, where the precision of the old 



