Internal combustion engines, in common with all heat engines, derive their capacity for work from a cycle of operations which comprises the supply of heat at a high temperature followed by the rejection of heat at a much lower temperature. The difference between the two quantities of heat represents the maximum amount of energy which can be converted into useful work. In the familiar piston-type internal combustion engine, the heat supply is maintained by burning a suitable fuel in air, and heat is rejected largely in the exhaust gases. With heat engines in general, it is true that the higher the temperature of the heat supply, the greater the efficiency of the engine. There are, however, limitations to the temperature at which an engine can operate. These are imposed by the properties of the materials used in its construction, and by the necessity of maintaining satisfactory lubrication in all circumstances.

The spade, or snow shovel, is an item of equipment required by any community living in the snow, particularly in the accumulation area of an ice sheet, where any object placed on the snow is eventually buried beneath a continually rising surface. Roald Amundsen, Alfred Wegener, R. E. Byrd, A. R. Glen and others have described the hours and sometimes days spent by members of their expeditions moving snow by hand. The Norwegian-British-Swedish Antarctic Expedition, 1949–52 was no exception. Some shovelling is unavoidable, being a consequence of natural accumulation, but much results from the burial of stores and equipment under snowdrifts caused either by the objects themselves or by their neighbours.

During the summer of 1954 the Royal Canadian Navy arctic patrol vessel Labrador, Captain O. C. S. Robertson, R.C.N., made her maiden voyage through the North West Passage. She left Halifax on 23 July. After calling at Resolute, Cornwallis Island, on 31 July, she returned to Craig Harbour in order to pick up an Eskimo family and transport them to Alexandra Fiord, farther up the east coast of Ellesmere Island. The Royal Canadian Mounted Police post at Alexandra Fiord was resupplied by the Labrador at this time.