Down-wasting has affected southern glaciers in New Zealand later than northern glaciers under the influence of a southward rising snow line which is attributed to a southerly shift in prevailing wind belts. Evidence from the Hooker Glacier indicates that the present period of wasting is the fourth of a series which began about 200 years ago.

As the firn line rises a glacier is planed in the ablation zone so that successive surfaces are parallel to the original surface, which shows that ablation is more active for a short distance below the fern line than near the terminal face. A period of accelerated terminal retreat can result from parallel down-wasting without a correlative acceleration in the rate of climatic change.

At Eqe, on the western border of the Greenland Ice Cap, measurements of the crystals by Seligman’s method give a mean crystal diameter of 2.16 cm. at a place where the ice velocity is ceto m.fday. The “heterometry index” measured from granulometric curves by Cailleux’s method shows that melting, active ice crystals have reasonably homogeneous dimensions, with a mean diameter from 2 to 2.4 cm.

The hardness observations taken in the Canadian Snow Survey are analysed and found to depend on snow density, temperature, and crystal size. This strength property of the snow is found to be highly variable and the variability is attributed to unstable bonding between individual snow grains.

The Fitz Roy district, on the margin of the Patagonian ice field (“Hielo continental”), is subject to continual and very strong west winds of high humidity. Glaciers descend to a very low level. Ablation by rain plays an important part, and contributes to some surface features, such as thin vertical sheets of ice, hummocks and dirt cones (a new theory of the origin of which is given). The summits of aiguilles, always covered with glazed frost in the Fitz Roy area, are incrusted with very heavy deposits of rime in the Cerro Torre and especially in the Cerro Grande areas. This forms huge comices and “feathered snow” to leeward.

Density of single crystals of ice from the Mendenhall Glacier near Juneau, Alaska, a temperate glacier, was determined by the hydrostatic weighing method. It was found that the densities of single crystals are slightly but measurably variable from one crystal to another. The values range from a minimum of 0.91712 gm./cm.3 to a maximum of 0.91728 gm./cm.3, when corrected for −3.5° C., for the eight crystals measured. Any imperfections such as Tyndall figures (hexagonal prismatic voids) were immediately evident in the density determinations, and correction for these imperfections give a corrected density essentially the same as that of clear specimens. Two clear crystal aggregate specimens tested had a lower density than the pure single ice crystals. An error computation gives the value of the estimated maximum error of the density determinations as ±2.1×10−5 gm./cm.3.

The Barnes Ice Cap on Baffin Island, N.W.T., Canada, was investigated during the summer of 1950. This ice cap, some 6000 sq. km. in extent, appears to have an approximately balanced budget, and yet there is no firn on its surface. It is postulated that its nourishment is by superimposed ice due to immediate refreezing of much of the melt water of summer. It is further inferred that a similar process nourishes many Arctic glaciers and ice caps where elevation, precipitation and temperature are all low. The name “Baffin Type” is proposed for these in the classification of glaciers.

Using the shadow-photograph method the processes of growth of disc crystals and of ice dendrites formed in water are studied. A mechanism of dendritic crystal growth is suggested.

Glaciological studies during the British Ruwenzori Expedition, 1052, included assessment of the extent of Pleistocene glaciation and detailed study of the late-glacial and post-glacial fluctuations of two of the glaciers originating in the Stanley Plateau. Correlation between photographs taken by earlier expeditions, the stratigraphy of lake site excavations and lichen re-colonization provide a good preliminary basis for assessing the climatic fluctuations. Stratification in existing glaciers appears to link up satisfactorily with meteorological observations to indicate two ablation phases annually.

The group of corries on Croaghaun Mountain on Achill Island is described. The existence of these corries and the absence of any extraneous drift from the mountain is taken as evidence that the inland ice of Co. Mayo did not extend far beyond the present coast. The relation of the corries to the local topography is described, and the effect of the topography on the apparent snow line is discussed. The probable snow line of the main glaciation of the west of Ireland is shown to be in the neighbourhood of 1250 ft. O.D. (384 m.) but may have been as low as 1000 ft. O.D. (305 m.) and that of the Late-glacial period in the neighbourhood of 1750 ft. O.D. (533 m.).

Two Eppley pyrheliometers were used to measure incoming and reflected sun and sky radiation over a saturated, melting snowpack. Albedo values computed from these measurements varied strongly, not only with snow surface conditions, but also diurnally with the angle of the sun, and from clear to cloudy skies. On clear days minimum albedo in the afternoon was approximately 35 per cent less than the maximum in early morning; a secondary maximum occurred at sunset. Also, midday albedos were higher under cloudy skies than under clear skies. These variations appear to relate primarily to changes in angle of incident radiation, and secondarily to changes in the physical structure of the snow surface. Spectral changes in incident radiation are also a possible factor.