Although I have quoted a Weather Bureau publication—because it happened to lie nearest at hand—the example selected is a fair specimen of the loose language of a majority of writers on atmospheric optics. In fact, the vocabulary is so confused that one can hardly write of any but the commonest of the photometeors without defining each term he uses; and I am not sure that even the names of the commonest are wholly unequivocal. In a recent number of Nature—a journal which is usually a purist in scientific English—the beautiful circumzenithal arc, Mascart's "upper quasi-tangent arc of the halo of 46 degrees," was referred to as a "zenith rainbow." Still more startling is it to find the new edition of Wood's "Physical Optics" ignoring the term "corona" altogether in describing the diffraction rings around the sun and moon.
In contrast to the prevailing confusion in the English vocabulary of this subject, we find that the labors of Pernter have led to the adoption of a nearly uniform terminology in recent German literature; but this writer shares with his compatriots a prejudice in favor of native terms that detracts much from the value of his contributions to the universal language of science. Thus, while he has adopted the Greek word "halo," he prefers to call a corona a "Kranz," and he clings to "Hof" as a general name for the heliocentric circles of all kinds. In fact, very few Greek or Latin names appear anywhere in his great treatise on atmospheric optics. Of course, this fact is merely typical of the almost universal preference of German science for linguistic isolation; a subject too large to enter upon here.
In French, the complicated terminology of halos was set in order by Auguste Bravais, and his labors have been admirably seconded in our own time by Louis Besson. Fortunately French science still prefers a Græco-Latin vocabulary, and the terms it introduces are easily taken over into English. No adequate account of halos has yet appeared in our language. Whoever undertakes to write one will hardly err in adopting the Bravais-Besson terminology en bloc, with only the necessary idiomatic modifications and without regard to the practise of earlier English writers on the same subject.
In the brief space remaining at my disposal I think I can not do better than to refer specifically to a few meteorological terms, of more or less recent origin, that deserve a wider use in scientific literature than they now enjoy.
Beginning at the top of the alphabet, I find that the branch of meteorology dealing with upper-air research is not yet known to all meteorologists as "aerology." This term, proposed by Köppen, and officially adopted at the Milan meeting of the International Commission for Scientific Aeronautics in 1906, is so well adapted to fill a serious gap in our vocabulary that one is surprised at the slow progress it has made in English. This is all the more surprising because, in
