THOUGH the special and continuous needs of meteorology, terrestrial magnetism and allied sciences for systematic observations over wide areas and in high latitudes had been felt long before 1882-83, it was not until then that a large-scale effort was made by twelve countries to study events in those subjects through a full year according to an agreed plan. In collaboration with Canada, Britain's share in that First International Polar Year, as the twelve months ending August 1883 has come to be called, was to equip a party under Capt. Dawson, R.E., for continuous observations in meteorology, terrestrial magnetism and aurora to be carried out at Fort Rae, a trading outpost of the Hudson's Bay Company on the Great Slave Lake, North-West Canada. Practically and scientifically, from the point of view of inter-national collaboration as well as that of Britain's own participation in it, the year's activities were completely successful. As the jubilee of that First Polar Year approached, it was felt in many quarters that no time could be more appropriate for a repetition on a much more extensive and intensive basis. In the three primary subjects then investigated, advances in recent years have been large, and mainly all in the direction of indicating that further progress depended on the gathering of more precise observational material from a still wider field and to the limits of the atmosphere. The sequences of weather changes over limited regions like Britain in moderate latitudes might well be determined by conditions in the stratosphere far to the north or south, days or weeks ahead: the short-period irregular changes in the earth's magnetic field, known to be intimately associated with the state of ionisation in the conducting layers of the high atmosphere, seemed to be bound up with auroral activity on one hand and the interruption of long-distance wireless communication on the other. To a few even it has seemed not improbable that these two domains, the apparently locally determined meteorology and the more cosmically produced aurora and its effect on the earth's magnetic field through the intermediary of the ionosphere, might be interconnected. Such were the questions: in many cases speculation and theory had outstripped fact.