THE
NATIONAL GEOGRAPHIC MAGAZINE.
GEOGRAPHY OF THE AIR.
ANNUAL REPORT BY VICE-PRESIDENT
A. W. GREELY.
In fulfilling the duties growing out of his official position inconnection with this Society, your Vice-President of the Geography ofthe Air has been so closely occupied with executive and other officialduties devolving upon him as to preclude his giving that amount oftime and labor to this annual report that the subject merits. Indeed,no report would be submitted this year had it not seemed better toinsure a continuity of these annual addresses, even if one of themmight not be up to the high standard which should be maintained forthem.
It must have impressed every general reader of scientific journalsthat the past year has been marked by the publication of an unusualnumber of controversial articles relating entirely or in part tometeorology. Some of the discussions of this subject appear to be inthe nature of speculation, which, by good authority, is defined to be"chiefly the work of the imagination, and has little to do withrealities." The status of the meteorological discussion which has beengoing on for some time seems to be this: A number of men, applyingthemselves to investigation in separate branches or stages of the samescience, are attempting to reconcile their views, which, based as theyare upon entirely different processes of investigation, are notentirely accordant. Some, at least, of these writers are stillapparently groping in the preliminary, the "natural history" stage ofthe [p. 42]science of meteorology, while one alone stands as theexponent of the "natural philosophy" of meteorology.
To me it seems that it could not have failed to impress any interestedreader who has followed the late publications on the convectionaltheory that, in order to clear the ground for definite meteorologicaldiscussion, it is necessary to determine the exact meaning of thevarious technical terms employed by the various writers. Whether fromlooseness of verbiage originally or from the not infrequent habit ofdisputants when worsted to change their ground by claiming to bemisunderstood, we find that some writers are unwilling either to standby their first criticisms or to openly abandon them; they prefer toexplain away their defective statements and gradually shift around topositions almost diametrically opposed to those originally assumed.
The generally accepted theory as to cyclones attributes theirinitiatory formation to an unequal distribution of temperature withresulting mean diminution of pressure, and the movement of the airfrom places of high to places of low pressure, the lower air ascendingwith a gyratory motion, while air particles moving from oppositedirections form couples which produce rotation. When energetic motionsraise the ascending air to such a height that the temperature, cooleddynamically in ascending, goes below the dew-point, then the greatstore of latent heat thereby set free becomes, it is ass