108 ECONOMIC GEOLOGY. 



Raymond, R. W, The World's Product of Silver. Iron^ n. s. vol. vii. 



p. 132. 

 Gives the production in various countries, as estimated by different 

 authors from 1800 to 1867. 



Saward, F. E. The Coal Trade. Neiu Yorlc. 



Statistics of i)roduction for the chief countries of the world, hut 

 especially for the United States. 



Schmidt, Dr. Adolf. Iron Manufacture in Missouri. A General 



lievicw of the Metallurgical Districts and their llesourccs. Trans. 



Ac. Sc. St. Louis, vol. iii. no. 3, pp. 261-272. 



i. Eastern ore region, comprising 4 districts; ii. Central ore region ; 



iii. Western ore region ; iv. Southern ore region. These regions are 



described under the heads Extent, Means of communication, and Ite- 



sources and their devetojjment. G. A. L. 



Schwind, P. v. Eine neue Bauregel fiir die Salzberge. [Xew Eule 

 for working Salt-Mincs.] Berg- Hi'Ut. Jalirh. Bd. xxiv. p. 299. 



An investigation of the proper height to be given between the levels 

 in mines that are worked by dissolving out the salt with a stream 

 of fresh water, the conclusion being that water cannot easily exhaust 

 a cone of ground more than 10 fathoms high. H. B. 



Simms, F. W. Practical Tunnelling. Ed. 3. Revised by D. K. 



Clark. Plates. 8vo. London. 

 Geological notes on Bletchingley and Saltwood Tunnels in Kent. 

 Notes on St. Gothard, Mont Cenis, and other tunnels, by the Editor. 



Sola, F. A. Quicksilver. Iron, n. s. vol. viii. p. 712. 

 A description of Almaden Mine and works. 



' Stohr, Em. Katechismus der Bergbankunde. 48 woodcuts. Vienna. 



Svedelius, G. T. f. bermiistarens vid guldvaskerierna i finska Lapp- 

 marken till Bergsstyrelsen afgifna beriittelsc om guldletnings och 

 vaskningsarbetct under ar 1875. [Report on the Gold-digging and 

 Gold-washing at Einlandic Gold-works in 1875.] Pp. 18. 8vo. 

 Helsingfors. 



Erom 1870 gold has been washed at the River Tvalojoki. Statistics 

 of yield are given. . • 



Tholander, H. Experimental Researches on the Reduction of Iron 

 Ore, and on the effect of roasting upon Magnetites and Haematites. 

 Iron, n. s. vol. viii. pp. 418, 482 [the parts before not geological]. 



Topley, W. Water Supply and Public Health. Poid. Set. Rev. vol. 



XV. pp. 31-45. 

 Refers to the influence of agricultural drainage on springs and 

 streams, hardness of water, yield of springs within the Thames Basin, &c. 



