3o6 JOSEPH STRUTHERS 



In one of the Ceylon mines near Caltura the graphite 

 occurs in a series of veins in gneiss which has become converted 

 to a depth of 36 feet, into a mass resembhng laterite. The 

 indications point to the deposition of the carbon by the de- 

 composition of hydrocarbon vapors, forming a true vein. 



The Ceylon mining industry, which is entirely in the 

 hands of the natives, has been profitable for many years, 

 chiefly on account of the purity and consequent high value of 

 the product. The method of mining is extremely primitive. 

 A shaft is sunk to the level of the ground water (from 40 to 

 200 feet), and drifts are cut from the bottom of the shaft 

 until the air is so bad that the lamps of the miners will no 

 longer burn; the ground is then stopped upward, the waste 

 being dropped behind until the shaft is filled. In some cases 

 the veins are followed by open cuts and galleries. The under- 

 ground workings are roughly timbered, and powder is used 

 to break the rock. The ore is hoisted by windlass and bucket, 

 or passed out by hand. A peculiar feature of the industry 

 is the opposition to the installation of modern mining ma- 

 chinery and methods, on the ground that the new conditions 

 might be less satisfactory than the older and fairly profitable 

 ones. The mined product is famous for its purity, the analysis 

 of several samples showing a carbon content of from 99.283 

 to 99.792 per cent. 



In Austria graphite occurs in the provinces of Bohemia, 

 Styria, Moravia, Carinthia, and lower Austria. The chief 

 producing mines are at Schwarzbach, in Bohemia. The de- 

 posits, which are lenticular, occur in gneiss, in parallel beds, 

 extending over an area 14 miles long by 10 miles wide. 



In Styria, which ranks second in importance, there is 

 found a highly metamorphosed system of carboniferous shales, 

 clay slates, Hmestones, and conglomerates with coal seams, 

 the coal of which has passed into graphite. It is very com- 

 pact, very pure, and often extremely hard, in some cases 

 retaining exactly the appearance of the coal from which it 

 has been derived. The graphite region extends from Leoben 

 to St. Lorenzen, a distance of 25 miles. The most important 

 deposits are at St. Michael, where five parallel beds, varying 

 in thickness from a few inches to several feet, and occurring 



