274 THE POPULAR SCIENCE MONTHLY 



terminology is so terrifying that we are thankful the meteorologists 

 had individual names before he got hold of them ; otherwise we shudder 

 to think what he might have done in the way of nomenclature! The 

 same ingenious Frenchman invented an instrument for measuring the 

 sensible temperature which he called at first the " calorisoustractom- 

 eter " ; but later he took pity on humanity and changed its name to 

 " deperditometer." 



Of the two evils — a clumsy term or none at all — the former is cer- 

 tainly to be preferred. There can be no progress in ideas without a 

 corresponding progress in language. This fact is emphasized by 

 Whewell; and he cites in illustration the cases of Caesalpinus in botany, 

 and Willughby in ichthyology, each of whom introduced excellent sys- 

 tems of classification which failed to take root or produce any lasting 

 effect among naturalists because they were not accompanied by corre- 

 sponding nomenclatures. No one recognized this truth more clearly 

 than Linnaeus, whose great contributions to botany were surpassed by his 

 contributions to the language of botany. Whewell quotes a maxim 

 from Linnaeus's " Botanical Philosophy," 



Nomina si nescis perit et cognitio rerum, 



which ought to be taken to heart by the many scientific men of to-day 

 who are conspicuously shirking their obligations to the technical 

 vocabulary. 



In the history of meteorology there are innumerable instances of 

 important ideas that led a precarious existence for years, almost ignored 

 by meteorologists at large, because no one had crystallized them by giv- 

 ing them names. Think of the number of conceptions that owe their 

 present defmiteness in our minds to the felicitous terminizing of Ealph 

 Abercromby ! The seven typical forms of isobars are familiar ex- 

 amples. Another is the generalization " recurrence," under which 

 term Abercromby united the many cases of the supposed tendency of 

 particular types of unseasonable weather to occur from year to year at 

 about the same period — Indian summer, the " Ice Saints," the 

 " Lammas floods," the " January thaw," the " borrowing days," and a 

 number of other similar interruptions in the regular march of the sea- 

 sons — all of them more or less elusive when submitted to a rigorous 

 analysis, but none the less deeply-rooted conceptions in the popular 

 mind. Individually these supposed occurrences are familiar to all 

 meteorologists, but we should probably sometimes lose sight of their 

 generic similarity had not Abercromby given them a handy generic 

 name. 



Probably in no branch of science is the vocabulary more confused 

 than in atmospheric optics ; especially in English. This particular sub- 

 ject affords so many examples of the vices of the existing language of 

 meteorology that we may profitably consider it at some length. 



