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Climatology and Meteorology.—In a course of lectures dealing with the present status of meteorology the subject of climate, upon which I have the honor to address you this afternoon, finds an appropriate place. For meteorology and climatology are interdependent, and it is impossible to distinguish very sharply between them. In a strict sense, meteorology deals with the physics of the atmosphere, and those of you who have attended the preceding lectures in this course have listened to able discussions of the physical problems with which meteorologists are to-day concerned. The view taken by meteorology is largely theoretical, but the main object in the solution of most of these problems is to make this science of immediate practical service to man, in improving and extending our weather-forecasts.

When the term meteorology is employed in its broadest sense, climatology is a subdivision of meteorology. Climatology is largely descriptive. It rests upon physics and geography, the latter being a very prominent factor. In fact, climatology may almost be defined as geographical meteorology. The main object of climatology is also to be of practical service to man. Its method of treatment lays the most emphasis upon the elements which are of the most importance to life. Climate and health, climate and industries, climate and crops, climate and transportation—these are subjects of vital human interest. It is my privilege this afternoon to suggest a few of the points of contact between man and his climate. If my discussion seems disjointed and haphazard, I beg of you to remember that the subject is one of the widest possible range; it concerns all men, in all parts of the world. To select from this immense body of facts the few which it is possible to touch upon in an hour is like trying to decide which of a thousand snowflakes is the most symmetrical; or to determine, in a wonderful view across the snow-covered mountains on a brilliant winter's day, whether it is the sun, or the crisp air, or the snow, or the contour of the hills, or the grouping of the trees, or the picturesque farmhouses, which really contribute most to make the picture what it is.

The Climatic Zones.—So great is the variety of climates to be found in the world that it has long been customary to classify these climates into certain broad belts, which we call the zones. These were first suggested, on purely astronomical grounds, in the times of the early Greek philosophers and geographers. It is to be noted