The Floor of the Pacific Ocean 251 



consisted of a rectangular platform carrying deckhouses, 

 mounted on six hollow lenticular rollers, each about 40 feet 

 diameter and 12 feet thick, actuated by engines of 150 horse- 

 power, and an engine of 500 horse-power works a screw- 

 propeller, which rotates between the pairs of rollers. The 

 friction of the water should thus be reduced to a minimum, 

 as the boat rolls over it without cutting through it. 



Feb. nth, 447th meeting. Sir A. Geikie gave a summary 

 of the results of Admiralty soundings in the Pacific. Sub- 

 marine peaks had been discovered, over areas hundreds of 

 square miles in extent, with bases averaging about 20 miles 

 wide and with flat tops, which are 25 or 26 fathoms below 

 high-water mark, and do not vary in depth more than a 

 few feet. These must be the cinder cones of volcanoes, now 

 ^extinct, which the waves have cut down to the level where 

 they ceased to have any erosive power. On three submarine 

 peaks corals had grown, and atolls were being formed. 



March nth, 448th meeting. Sir John Evans called 

 attention to the discovery by Mr. Joseph Landon, of Saltley, 

 near Birmingham, in the highland gravels of the Rea, of at 

 least one well-formed palaeolith, made of quartzite. The 

 absence of these implements from the region north of a line 

 drawn from the mouth of the Severn to the Wash had been 

 explained by supposing it to have been then covered by ice, 

 but as similar palaeoliths had already been found at Creswell 

 Crags in north-east Derbyshire, 1 non-discovery might be 

 the better reason, and a careful search in the older gravels of 

 northern rivers might result in a large extension of the area 

 occupied by palaeolithic man. 



June 1 7th, 45ist meeting. Dr. Russell gave an account 

 of experiments on the action of metals and some other 

 bodies on photographic plates which he had been describing 

 that afternoon to the Royal Society. When repeating 

 Becquerel's experiments on uranium, he had found zinc to 

 act in the same kind of way, a fact which, though he was not 

 then aware of it, had been already observed by Colston. 



1 See J. M. Mello, Quart. Jour. Geol. Soc. 1876, pages 240-244. and 

 W. B. Dawkins, ibid, pages 249-256. 



