THE LANGUAGE OF METEOROLOGY 277 



spite of its Greek etymology, it was promptly accepted by the Germans, 

 and is now fully established in their language. The expression " scien- 

 tific aeronautics," still incorporated in the name of the international 

 commission that has the oversight of aerological matters, is an obvious 

 misnomer as applied to the exploration of the free atmosphere, notwith- 

 standing the fact that aeronautical methods and appliances are largely 

 used in this field of research. 



The most remarkable occurrence in the history of aerology was the 

 discovery, in 1902, of a region of the atmosphere originally called by 

 its discoverer the " isothermal layer " ; a name that he has since aban- 

 doned in favor of " stratosphere." A number of other names have 

 been proposed as alternatives — in some cases for reasons that, to any 

 one familiar with the natural history of scientific terms, seem decidedly 

 frivolous. Thus, some of our English confreres objected to the original 

 name because there was no certainty that the so-called " layer " had an 

 upper boundary — an objection that has perhaps been disponed of 

 recently by Dr. Alfred "Wegener. Mr. Dines, one of the ablest 

 of aerologists. prefers to speak only of "isothermal columns" in the 

 atmosphere; but this plan leaves the important stratum as a whole 

 without a name. There is every indication at present that Teisserenc 

 de Bort's second term, " stratosphere," will ultimately prevail. It 

 commends itself by its consonance with the term " troposphere," ap- 

 plied by the same investigator to the region of clouds and convective 

 disturbances, and with Wegener's recent tentative names for supposed 

 higher strata of the atmosphere — " hydrogensphere " and " geoco- 

 roniumsphere " ; and all of these conform to the well-established ter- 

 minology of " atmosphere," " hydrosphere " and " lithosphere." 



Meteorology has recently profited, as to terminology and otherwise, 

 by the writings of Henryk Arctowski, who, though a Pole by birth and 

 a Belgian by adoption, wields a very facile pen in English. M. Arc- 

 towski is responsible for the convenient words " pleion " and " anti- 

 pleion," denoting, respectively, regions of positive and negative depar- 

 ture from a normal. Thus, a temperature pleion. or " thermopleion," 2 

 lay over western Europe during most of the summer and early autumn 

 of 1911. Lines of equal positive and negative departure from normal 

 temperature (not " anomalies," which are departures of local means 

 from the means of latitude circles) were unnamed until Arctowski 

 called them, respectively, " hypertherms " and " hypotherms." All 

 these terms are correctly formed from Greek roots, are easily assimilable 

 into our language, and are well fitted to give definiteness to a group of 

 ideas that formerly suffered in this respect by the lack of a terminology. 



2 M. Arctowski 's terminology is not quite consistent, since he does not speak 

 of " thermoantipleions, " but of " thermomeions. " As ' ' antipleion ; ' is an 

 awkward form in combinations, it is unfortunate that it was adopted as the 

 generic term. ' ' Meion ' ' is preferable. 



