DURNTEN LIGNITES. 149 



Oberberg and Binzberg. On the Oberberg (between 1854, in 

 which year the underground working was commenced, and June 

 1862) 8090 square fathoms of the carboniferous deposit were 

 dug out, and 736,800 hundredweight of fresh lignite, furnishing 

 about 48.2,000 hundredweight of dry coal, were obtained. This 

 quantity represents approximately in heating-effect 14,030 cords 

 of birch wood or 22,044 cords of fir wood (of 108 cubic feet to 

 the cord). In the first three years the workings produced yearly 

 more than 100,000 hundredweight; but in the year 1862 the 

 produce fell to 29,185 hundredweight; and it may be foreseen 

 that the supply will shortly be exhausted. 



Mining was commenced in the deposits on the Binzberg in 

 1862 ; and 29,552 hundredweight of lignite were obtained in the 

 first year from 770 square rods. In a north-westerly direction 

 the deposit disappears for a short distance ; but it is again found 

 in the Schoneich near Unterwetzikon, about 1| Swiss mile 

 fro en Diirnten; and here it has also been worked since 1862. 

 In 1865, 251 square fathoms had been removed, with a yield of 

 16,536 hundredweight of saleable coal. The thickness of the 

 deposit containing marketable coal is here 2| feet; in some 

 spots it increases to 5 feet, but in others decreases to 2 feet or 

 even less. The carboniferous area here contains about 40,000 

 square feet. It was probably connected formerly with the coal- 

 deposit of Diirnten, and was produced in the same manner and 

 at the same time. At the Oberberg, however, its thickness was 

 much greater. Here and there it was as much as 12 feet thick, 

 whilst in other places it diminished to 5, 3, and 2J feet thick. The 

 mean thickness of saleable coal has been estimated at 3 '75 feet. 

 Between the lignites bands of loam occur, the number of which 

 is determined by the thickness of the whole deposit : where this 

 was 12 feet thick it was traversed by six bands ; but where it was 

 2 feet thick there were only two bands. 



The lignite- deposit of Diirnten rests upon a fine yellowish- 

 brown clay. A shaft which was sunk through this to a depth 

 of 30 feet below the lignite showed that at the bottom there is 

 a mass of rolled stones imbedded in the clay ; but the Miocene 

 was not reached, as the influx of water prevented the shaft from 

 being dug deeper. In one place there are many rolled pebbles 

 in the clay immediately below the lignite-deposit ; they are of 



