A CONTRIBUTION TO THE STUDY OF ICE-STRUCTURES 9 



terminated at the lower end in a bulb about a quarter of an inch in diameter. The bulbous 

 extremities were chiefly occupied by gas, but the stems above were almost fully 

 occupied by saccharoidal crystalline matter. The ice itself was in platy form arranged 

 in a vertical direction. The plates averaged an eighth of an inch across, but extended 

 for several inches in the vertical direction. Frequently several adjacent individuals 

 were in optical continuity, producing flash faces up to three-quarters of an inch across. 



4. SHALLOW LAKE 



Situated in a slight depression in the lee of the ridge immediately north of the 

 head of Pony Gully in proximity to Split Rock. On account of the basin being an 



Snow 



JG Ins. 



INeve . 



of spongy crystalline 



r l Ft. 8 ins- of clear prismatic 

 Ice becoming less tTa-nsparent 

 lov<er down. Stratification losing 

 definition below, outlined, by 

 bubbles up to one sixth inch diaw., 

 also Strings of bubbles arranged 

 vertically. 



/6 I-ns. of transparent platy Ice 

 (with vertical brine tracts. 



JZ Ins. of Vhite,enamel-liKe, 

 granular Cryohydrates. 



Gravel 



Rock 



V 



Fig. 2. Shallow Lake Section 



imperfect container, much of the thaw-water drains away in the summer-time. 

 The ice-mass is more of the nature of an ice-slab formed by drift accumulations. 

 During the autumn much of the ice from the fresher portions was quarried for domestic 

 purposes. Towards one corner, where the basin was well contained, the ice proved to 

 be very saline. There the ice at the bottom was found to be a completely crystallised 

 concentrated brine, and so presented specially interesting features (Fig. 2). The 

 depth of solid ice was not more than two feet six inches, though irregular accumulations 

 of snow and neve were scattered over the surface. No growth of alga was to be seen there- 

 abouts. Doubtless the absence of organic growth accounted for the enamel- white colour 

 of the saline ice from this basin, in distinction to the yellow colour of that from the two 



