I. INTRODUCTORY 



During the winter months much time was spent in investigating the composition, 

 texture, and fabric of the varied ice-forms in the vicinity of Cape Royds.* For this work 

 a Low-temperature Laboratory was constructed in which the temperature was always 

 well below freezing-point. Samples could be treated there in much the same way as 

 other rocks and minerals in an ordinary laboratory. A ready method of studying the 

 crystalline fabric of the specimens was discovered accidentally and happened in this 

 way. It was noted that the large blocks of very cold ice brought into the Hut and piled 

 up in the big melters over the stove quickly became frosted over by the freezing upon 

 them of vapour rising from the bottom of the pot. 



In this way, within a few minutes, all the crystal individuals were differentiated to 

 the eye, for the frost additions were microscopic plates developed in optical continuity 

 with the particular individuals upon which they formed. The effect was that every 

 crystal gave a bright reflection when held at a particular angle. 



The method of procedure adopted for the investigations was to bring the specimens 

 inside in as cold a condition as possible and place them in the colder portions of the com- 

 paratively moist Hut. After a few minutes, upon moving them about in the light, the 

 grain structure could be observed with ease, by reason of the diverse scintillations. 



On some moonlight occasions in the winter, depositions of the kind, formed naturally 

 from frost, were observed on the surface ice of the lakes. 



With the object of photographing bubbles and other objects contained in the ice, 

 slabs of a fair thickness were first sawn, then reduced to the required thinness by rubbing 

 down on a slightly warm plate, tilted at a small angle to carry off the water. 



The Buchanan Hydrometer was used for specific gravity determinations of the thaw 

 water. 



For pure water for chemical work freshly fallen snow and some of the neves in the 

 vicinity were used, and found to be actually purer than the distilled water brought 

 from New Zealand. 



* The study of ice and ice-forms was one of my duties on the British Antarctic Expedition, 

 1907-1909. On return a short popular note to form an appendix to The Heart of the Antarctic was 

 forwarded to London on brief notice. 



When the Geological Memoir was in preparation by Professor David and Mr. Priestley, I was 

 to have co-operated at their request, but preparations for the Australasian Antarctic Expedition, 

 1911-1914, intervened. Vol. I of Geology has now appeared with excellent chapters on Glaciology, 

 and the notes now submitted are merely fragments in amplification. For several reasons there 

 has been considerable delay in publication of this matter, which was ready four years ago. Since 

 then my observations have been much widened, and will appear shortly in the Scientific Results 

 of the Australasian Antarctic Expedition, 1911-1914. 



Regret is to be expressed at the loss in transit between Adelaide and Sydney of a consignment 

 of brines and cryohydrates brought back for examination ; with them was lost some valuable 

 information. — D.M., December 1915. 



