September 14, 1917] 



SCIENCE 



265 



we fiiid the following: "Aerography, descrip- 

 tion of the atmosphere. 1753 Chambers Cycl. 

 Supp., 'Aerography, a description of the air, 

 or atmosphere, its limits, dimensions, proper- 

 ties, etc' 1S18 in Todd." This long-forgotten 

 synonym for " meteorology " Professor McAdie 

 seeks to restore as a title for the study of the 

 atmosphere particularly in relation to human 

 safety and progress. The word " meteorology " 

 is so well-intrenched, however, and so com- 

 prehensive, that it is not likely, in our gen- 

 eration at least, to be replaced by " aero- 

 graphy." 



The purpose and scope of the book are sum- 

 marized in the opening sentence of the pref- 

 ace, "... to present this new knowledge [of 

 about the last ten years] in a convenient form 

 even if considerably condensed." There is 

 much direct quotation. Thus we have here a 

 useful supplement to American text-books in 

 meteorology, of which the last comprehensive 

 one was published in 1912. The points em- 

 phasized are necessarily not the well-known 

 tenets of the science, but its recent develop- 

 ments. " Stress is laid on modern methods 

 of attack and the practical application of what- 

 ever knowledge is already available." The 

 most noteworthy feature is the exclusive use 

 of metric and absolute imits. 



Unfortunately, coherence and clearness seem 

 to have been sacrificed to brevity in the 

 attempt to make the book a college text; with 

 short chapters, numbered sections, and para- 

 graph headings. The successive chapters are : 

 "A brief history of meteorology; units and 

 symbols; temperature scales; thermodynamics 

 of the atmosphere; stratosphere and tropo- 

 sphere; the circulation of the atmosphere; 

 the major circulations; the minor circula- 

 tions; forecasting storms; the winds; the 

 water vapor of the atmosphere ; condensation ; 

 dust and microbes; atmospheric electricity; 

 precipitation; floods and notable storms; 

 frosts; [and] solar influences." The lack of 

 a more systematic arrangement of the material 

 probably will be a serious obstacle in the way 

 of the use of the book as a text-book. 



The subjects included are, for the most 

 part, well chosen, though many are too briefly 



discussed. The consistent use of metric units 

 of measurement and weight, and the absolute 

 scale of centigrade temperature and of atmos- 

 pheric pressure is highly commendable. The 

 author's tables in these units, and his inter- 

 pretations of aerodynamics place these com- 

 plexities within reach of the well-taught stu- 

 dent. The student, however, may be confused 

 in having absolute pressure units presented as 

 " kilobars " when they are commonly known 

 as " millibars." " Kilobar " has historic prec- 

 edence over " millibar," it is true ; but " milli- 

 bar " is the internationally accepted term. 



On account of omissions or the tantalizing 

 shortness in the treatment of many interesting 

 subjects, the reader may wish that Professor 

 McAdie's book were twice as long. Por ex- 

 ample, few students probably can understand 

 the brief explanation of energy used in expan- 

 sion (p. 43) ; and some may search in vain 

 for an explanation of the prevailing westerly 

 winds. Seeming contradictions are confusing : 

 thus, a statement of the presence of great polar 

 low pressures is followed by a mention of polar 

 high pressures (pp. 54 and 56). It is hard to 

 reconcile the following statement with all 

 other mentions of the temperatures of the 

 upper air: "10° A. Effective temperature 

 of space. At an elevation of 80 kilometers 

 (50 miles) the temperature ranges from 

 5° to 10° A." (p. 287). This is' contrary 

 to the radiation theory of the tempera- 

 tures of the stratosphere (pp. 50 and 51) ; 

 and up to 30 kilometers, at least, there is no 

 observational basis for this assumption. 

 Again, some one might ask why the tempera- 

 ture of the atmosphere is below the effective 

 temperature of space. In some places the dis- 

 cussion hinges on quantities depending on per- 

 haps three variables, of which only one is 

 stated: on p. 43, the weight of a cubic centi- 

 meter of dry air is stated without mention of 

 temperature and pressure; on p. 58, deflecting 

 force is evaluated without specification of the 

 latitude. Many of the erroneous or weak 

 places in the book are ascribable to brevity. 

 An error may be noted here (p. 139) : " [In 

 the atmosphere] if there should be no gradient 

 [of temperature], we shouild have the density 



