622 Geological Work done on board H. M.S. 'Challenger. 3 



Scoriae were only met with on one occasion, namely, on the hill called 

 " Cat's ears," at the entrance to Royal Sound ; but, as far as could be 

 decided by a view from the sea, they seemed to be by no means rare on 

 the southern coast, where the cliffs, worn by the violence of the south- 

 westerly gales, show sections of what undoubtedly is red scoriaceous 

 matter. The whalers whojrequent the harbours of the island chiefly for 

 sealing purposes, and from whom much valuable and reliable information 

 was obtained, affirmed the existence of an active volcano on the western 

 side of the island, as well as of springs of mineral water, both hot and 

 cold, and of petroleum. 



It is much to be regretted that our time was too limited to allow of our 

 visiting the but little -known coast of the western side of the island. 



The group of Heard and M'Donald islands was visited after leaving 

 Kerguelen. M'Donald, the smaller of the two, is, I believe, quite inacces- 

 sible. The ship anchored in Corinthian Bay, Heard Island, on the after- 

 noon of the 6th February, when I had the opportunity of spending about an 

 hour and a half on shore. The landing-place was at the head of the bay on 

 a flat sandy beach at the mouth of a river which comes out of one of the 

 magnificent glaciers which form a continuous ice- wall along the south- 

 western shores of the bay. Like all glacier-streams it was very muddy. 

 The island here is very narrow, not more than a mile broad, and the 

 sandy plain stretches from sea to sea ; it, in fact, forms the heads of 

 three bays, namely, Corinthian bay facing to the north-east, the open 

 sea towards the south-west, and a narrow bay which runs in between 

 two remarkable promontories on the north-east. The connexion of these 

 two promontories with the main island by means of this sandy plain is 

 so low that a depression of a few feet would suffice to separate them 

 from each other and from the mainland. The sand is very dark-coloured 

 and highly magnetic, and was being blown with such violence by the then 

 prevailing south-west wind, that it was necessary, when exposed to it, to 

 use some protection for the face. Nowhere have I seen the abrading 

 power of blown sand better exemplified than on the isolated rocks which 

 have rolled down from the heights above and remained fixed in the sandy 

 plain, exposed to the constant strong south-westerly gales, driving the 

 sharp volcanic sand against their sides. In this way they have frequently 

 been cut and dressed as by a mason's chisel. It is, however, not the 

 south-westerly winds alone which produce this effect; but from their 

 great predominance they have given the rocks the peculiar " sheared " 

 appearance, much resembling that assumed by the trees growing on a 

 coast exposed to the trade-winds. If favourably placed rocks be carefully 

 examined, the effect of every prevalent wind will be observed in the facets 

 which it has produced on the surface. The largest facet, and the one 

 which determines the general appearance of the rock, is the one turned 

 towards the west; and I do not doubt that the areas of the others would 

 afford useful information as to the relative prevalence of other winds. 



