Snow and ice from their mutations and from the part they play in nature as precipitation, agents of erosion and modifiers of climate come within the range severally of physics, meteorology, geology, physical geography, oceanography and climatology. The behaviour of ice crystals in glaciers has close connection with crystallography and metallurgy.

It may be of interest at this stage to recall the papers and discussions at meetings since the commencement of the activities of the Association for the Study of Snow and Ice until the war put a temporary end to them.

In the middle of last century, Agassiz, Tyndall and others showed that a glacier flowed faster at its centre than at its margin. Partly from experiments and partly from the assumption that it behaved like a river, it became generally accepted that it also flowed faster at the surface than lower down. This belief was held until ten or fifteen years ago although search through earlier literature shows that evidence was accumulating which might disprove this.

On 7 May 1939 Professor F. Alton Wade, Chief Geologist of Admiral Byrd’s Third Antarctic Expedition, which came to be known as the U.S. Antarctic Service Expedition 1939–41, wrote a letter in the course of which he expressed the view that the efforts of the various expeditions to the polar regions should be more closely coordinated than they had been in the past. He therefore asked me if the Association for the Study of Snow and Ice would be prepared to make suggestions for his glaciological programme, including methods, technique and apparatus. The Committee of the Association readily agreed and set aside a time for discussing this at the Association’s meeting on 12 July 1939.

This Survey, which, under the directorship of Mr. Gordon Manley, had made substantial progress until the war intervened, is to be resumed during the autumn of 1946. For a time the principal aim will again be to secure representative data relating to the occurrence of snow-cover at different altitudes in the various upland districts over the period October to June. To this end the Society is fortunate in having already been promised the help not only of a number of pre-war participators in the Survey but also of the Meteorological Office, Air Ministry. By the courtesy of the Director, Sir Nelson Johnson, records of the daily incidence of snow-cover (and where possible of its depth) at about 55 high-level meteorological stations are to be supplied to us month by month. In addition, Dr. J. Glasspoole of the British Climatology Division has suggested that a considerable number of the regular contributors to the official publication British Rainfall whose gauges are situated at altitudes of not less than 500 feet should be invited to co-operate. Dr W. A. Harwood, Superintendent of the Meteorological Office at Edinburgh, has kindly agreed to allow that office to be used as a clearing house for Scottish records, as before the war.

In the years immediately preceding the war more work on the causes of avalanches was done in Switzerland than in any other country. We in this country were kept well posted in the progress of the work by the willing cooperation of the Swiss and their permission for us to visit their avalanche research station on the Weissfluhjoch.

IN 1939 it was decided to leave a book in the Ben Nevis Hut in order that visitors might record the snow conditions there. The Scottish Mountaineering Club gave the necessary permission and much help. The register was brought down early in 1946, inspected and returned to the hut for further entries.

Many authorities have demonstrated that the hardness of ice varies inversely as the temperature, which is, of course, to be expected by analogy with metals. Recently Dr. E. Blackwelder1 caused some experiments to he made at a temperature of −78.5° C., the temperature of solid carbon dioxide. At this temperature the hardness of ice was found to be approximately 6, or that of orthoclase felspar. Hitherto it had been assumed that aerial corrosion of rocks close to glaciers and snow-fields was in the main due to rock dust. It now seems likely that when air temperatures fall very low, as for instance during blizzards, ice fragments or snow could abrade certain limestones and shales and even some igneous rocks. Ice and snow may therefore play a more important part in aerial erosion than had been suspected.

The crystallographic results of the Jungfraujoch Research Party’s investigations were published in the Proceedings of the Royal Society in August 1939. It has since occurred to me that insufficient attention was drawn to another factor affecting the movement and growth of the glacier grain, namely the possibility of pressure melting, followed by regelation. There are numerous air spaces between glacier grains at all stages until they approach the state of pure ice, and it seems natural that while two neighbouring grains (which are continually moving differentially to one another) arc in contact, pressure melting, will take place, and that when the film of water reaches an air space it will refreeze. The effect will become less as the firn passes into ice owing to the decrease in the amount of air space and the increased interlocking, of the grains, which makes their differential movement more difficult. Naturally, also, pressure melting would not take place at those points in the glacier which were appreciably below freezing point.

Shortly before the war this new word for the study of glaciology was coined in Central Europe. The Greek noun κρύος means “cold.” It is not clear why this word should be applied exclusively to cooled water; it could equally well be used for any cooled substance, for example carbon dioxide or ice cream.

A recent event of great importance has been the inception of officially sponsored snow research in Canada.

Hitherto large scale snow research has been almost entirely restricted to the Swiss and it is good to know that the Empire with its enormous opportunities will now be playing its part. The connection between the mechanics of soil and the mechanics of snow has been obvious for several years in Switzerland where the resources of the civil engineering laboratories have been made available for snow research. Dr. R. Haefeli, originally a civil engineer and head of the soil research department of the Eidgenossische Technische Hochschule in Zürich, has now become one of the foremost authorities on snow and ice. It is satisfactory to learn that this connection of ideas is being followed up in Canada. In England too a start has been made.

The photographing of snowflakes has been carried out for many years and has yielded valuable as well as beautiful results. But the unsubstantial nature of snow necessarily makes the process laborious and slow.