Five glacial phases are recognized in the area described. Two of these are represented by the deposits of ice-sheets from the north-east and north-west respectively; the other three were of local origin. The materials composing the drifts differ sufficiently to enable the stratigraphy to be seen clearly. This shows that the local ice caps alternated with the invading ice sheets—which brings out a point of considerable climatological interest in that it is clear that the local ice advanced not simultaneously with the invading ice sheets but alternated with them. The order in which the five phases occurred is well established, but the importance of the intervals between the phases is at present uncertain.

Accurate measurements by electrical means of temperatures at various levels in shelf ice, glaciers or ice caps are of themselves insufficient; they must be accompanied by data on densities at the same levels and on incoming and outgoing radiation, as well as other things. Depths of measurements must be known accurately, and changes in them due to changes in surface level must be recorded. Levels chosen should be , 1, 2, 4, 8, 16, 32 and 64 m., and readings (if repeated to ensure accuracy) need be taken only once daily down to 4 m. and weekly or so at lower levels. Measurements should be free of external influences such as heat from buildings or deep drifts. Only when all other necessary data are available and all precautions observed will it be possible to explain the thermal structure of the ice sheet as shown by the sub-surface measurements of temperature.

This paper concludes the earlier researches of the author and his colleagues on the development of glacier ice from the snow crystal. It traces the crystal growth down to the end of the glacier and records the distribution of large crystals in glacier tongues. Various agencies are suggested which might help in the proposed investigation of the mechanisms of growth of the crystals of glacier ice.