﻿524 Reviews — Lyman's Geology of Japan. 



blown sometimes one way, and sometimes another, and have dropped 

 powdery sulphur all about within a space of somewhat rectangular 

 shape, about 250 yards long from top to bottom, and 150 yards 

 wide across the valley, which here is broad and shallow, and slopes 

 steeply westward, falling about 325 feet from top to bottom of the 

 sulphur. There are no plants here, and the ground is covered with 

 rough blocks of stone of one foot, two feet, or even six feet or more 

 in diameter, a grey volcanic rock, trachytic porphyry containing 

 sanadine. Among these stones the sulphur has gathered to irregular 

 depths, in some hollows quite covering the stones like a snow-drift. 

 In some places the sulphur is burning quietly at a depth of a few 

 inches below its surface, and sending out fumes by small holes. 

 Further down hill the sulphur has been washed by the rains down 

 the bed of the stream now dry, and has collected into a solid pretty 

 pure mass, a foot or two, or even three, in thickness, but only a few 

 feet wide, though perhaps a hundred yards long." As would not be 

 unlikely, there is no drinkable water within a mile and a half; the 

 carriage to the shoi-e is difficult; and yet it is thought a small profit 

 might be made by working the deposit ; the experiment of dipping 

 up the molten sulphur is suggested, but no mention is made of any 

 possibility of condensing and thus economising the fumes so largely 

 given off. 



Iron seems only to occur in the forms of magnetic iron sand along 

 the shores of Volcano Bay, etc., and as bog iron ore in other places, 

 the whole amount present being hardly more than 100,000 tons. 



With regard to geology proper, extended knowledge of the ground 

 has reduced the number of formations into which the rocks had been 

 previously divided, so that, instead of the list formerly given, we 

 have now the following : — 



New Alluvium, perhaps up to 100 feet in thickness 



Old Alluvium ,, 100 ,, ,, 



New Volcanic EocJcs ,, 200 ,, ,, 



Toshibets Group, probably about 3000 „ „ 



Old Volcanic Rocks, perhaps „ 3000 „ „ 



Horumui (or Brown Coal-bearing) Group, 



probably about 6500 ,, „ 



Kamaikotan [Metamoj'phic), perhaps 3000 ,, „ 



The thicknesses, except those of the Toshibets and Horumui 

 groups, are not based on any measurements, but inferred from 

 general observations. 



Mr. Lyman has seen reason to abandon the Toshibets Kuril 

 division, and to include it with the Toshibets Karafto groups. 



In one of his reports specially geological he has not adopted 

 the chronological order of description, but inverted it, sacrificing the 

 advantage derivable from giving a comprehensive idea of consecutive 

 geological events, 



A great want is that of geological sections showing the structure 

 of the island, and the manner in which the different groups succeed 

 each other. Sections across the coal-beds are frequently given, 

 showing synclinal and anticlinal curves, the forms of which need 

 not as a general rule be necessarily those assumed for them from 

 observations on the dips taken at the surface, but we do not find a 



