452 



SCIENCE. 



[N. S. Vol. XII. No. 299. 



published in 1874, and much used some years 

 ago in American colleges. It speaks well for 

 the teachers of botany that this book has 

 proved so popular as to have gone through so 

 many editions, in spite of the fact that it has 

 not departed essentially from the scientific 

 sequence of topics, neither has it attempted to 

 introduce popular 'natural history' features 

 in place of the more difficult laboratory re- 

 quirements. The book contains three 'parts,' 

 the first of which deals with structural, the 

 second with physiological, and the third with 

 systematic botany. It may still be held up as 

 a model worthy of being followed by makers 

 of botanical text-books. 



Chaeles E. Bessey. 

 The XJniveesity of Nebraska. 



THE COAL FIELDS OF CHINA. 

 PROrESSOR Drake, of Tien-tsin, has lately 

 published a report on the coal fields in Shan-si 

 province, which he visited last autumn, especi- 

 ally those around Tse-chau, which were first 

 made known to the world by Baron von 

 Richthofen in 1870, and for the working of 

 which concessions have been granted to an 

 Anglo-Italian company. According to the ab- 

 stract in the London Times, the journey from 

 the coast is made across low-lying plains, and 

 then a plateau is ascended, on which the' coal 

 measures are found. The workable coal lies in 

 one bed, about 250 feet above a flint-bearing 

 limestone stratum, below which it is possible 

 that there is also coal. In Tse-chau the average 

 thickness of seam is probably not less than 22 

 feet, and at one place it is worked through a 

 shaft 329 feet deep. Streaks of shaly coal are 

 common in the part being mined, but there is 

 no waste coal taken out, and the proportion of 

 ash is little more than 10 per cent. There is no 

 waste material in the bed in any of the mines. 

 Professor Drake estimates that within the 150 

 square miles around Tsechau there are about 

 3000 million metric tons of coal, and it " must 

 be remembered that this area is only a little of 

 the ragged edge of the great coal fields of 

 Shan-si. Most of Shan-si has been found 

 underlaid by large coal beds. Richthofen esti- 

 mates that the anthracite coal alone of Shan-si 



amounts to 630,000 million tons, and that the 

 coal area is greater than that of Pennsylvania." 

 All the Tse-chau coal is anthracite, with a 

 specific gravity of 1.5, and it is hard enough to 

 support any weight put upon it in the blast 

 furnace. The proportion of sulphur is uni- 

 formly low, and that of ash also. A cursory 

 examination of the outcrops showed the iron 

 ore stratum to be 2 feet to 3 feet in thickness ; 

 the workings are limited to this narrow strip be- 

 cause the ore beds lie near the surface and can 

 be mined by open pits, whereas elsewhere deep 

 shafts and long tunnels would be needed. But 

 the small quantity of ore will probably never 

 justify extensive mining at a depth. Besides 

 coal and iron ore the district yields fire clays of 

 good quality for bricks and cheap pottery. 

 These are now much used by the Chinese for 

 household utensils. Sandstone occurs in abund- 

 ance and is extensively used by the Chinese ; 

 its fault is great friability. Massive limestones 

 are in great abundance and of good quality. 

 They vary in color from light gray to blue and 

 almost black. The soil is largely loess, and is 

 therefore fertile and highly cultivated, a dense 

 population being supported by agriculture. 

 The industries are centered round the mines. 

 Nearly all the coal is mined through shafts 

 varying in depth from 50 ft. to over 300 ft. 

 Very little is mined through inclines. No 

 steam is used for raising the coal to the surface, 

 and explosives are not employed. The work 

 is done with the windlass and pick. Tunnels 

 are run through the bed from the bottom of the 

 shaft, and at intervals along the tunnels large 

 quantities of coal are removed, leaving circular 

 chambers 40 ft. to 50 ft. in diameter, and thus 

 about 50,000 tons a year are brought to the 

 surface in the district. For local use, the coal 

 is carried away in little carts drawn by oxen, 

 but most of it is taken down the mountains by 

 pack animals, as the paths are very steep and 

 rough. It is 20 miles to the plains ; the paths 

 are about 13 ft. wide and are paved with stone. 

 But "the great thickness and the almost hori- 

 zontal position of this coal bed make it prac- 

 ticable, as suggested by Richthofen, for other 

 Shan-si coal beds, to run long lines of railroad 

 tunnels through the bed, and load the cars in 

 the mines for distant transportation." 



