Meteorology is essentially an _international_ science. The atmosphere knows no political boundaries, and the more it is studied the more strongly meteorologists are impressed with the fact that intimate relations exist between the atmospheric events of widely separated regions of the world. Thus, the great anticyclone that is built up every year over the cold interior of Siberia exercises an influence upon the weather of the United States; the behavior of the Indian monsoons has been found to have some connection with barometric conditions in South America; and fluctuations in the force of the trade winds are apparently of world-wide significance--whence these winds have been described as the “pulse” of the general atmospheric circulation. The French meteorologist L. Teisserenc de Bort called attention many years ago to the existence of what he called “centers of action”; viz., large permanent or semi-permanent areas of high and low barometric pressure, the variations of which correspond strikingly with the vicissitudes of wind and weather in countries thousands of miles distant. Last but not least, persistent attempts have been made to interpret all the weather happenings on our globe in terms of a fluctuating supply of radiant energy received from the sun. Fortunately meteorology has possessed an international organization for a great many years. The International Meteorological Organization was founded at a conference held at Leipzig in 1872, and was perfected at a formal congress of meteorologists convoked at Vienna in the following year. The International Meteorological Committee, which is the permanent working body of the organization, was established at the Vienna Congress. Finally, the organization was reconstituted at a conference held at Paris, by invitation of the French Government, in 1919. The International Committee consists of not more than twenty members, all of whom are directors of official meteorological services. It is supposed to meet at least once in three years. At less frequent intervals are held “conferences,” to which are invited representatives of all the meteorological services and the principal independent meteorological observatories of the world. Attached to the organization are several international “commissions,” which supervise and coordinate the work of meteorologists in various special fields. At the close of the year 1921 there were commissions on the following subjects: Agricultural Meteorology, Weather Telegraphy, Marine Meteorology, Solar Radiation, Application of Meteorology to Aerial Navigation, Réseau Mondial, and Polar Meteorology, Investigation of the Upper Air, Terrestrial Magnetism and Atmospheric Electricity, Study of Clouds. Each commission includes in its membership at least one member of the International Committee, besides a number of experts, from different countries, in the particular subject with which the commission is concerned.