Reviews — Report of the Coal Commission. 517 



In many such, parts of the Manto this impregnation has been so 

 general and so rich that the workmen have left only a few slender 

 pillars of it to support the roof ; and these are mostly pierced and 

 scored in pursuit of rich veins and fibres. On every side of the 

 caverns thus opened, galleries, extended on lines of ore nearly coin- 

 cident with the joints, form, as they interlace, an almost inextricable 

 labyrinth." 



The gold-mines in the province of Minas Geraes in Brazil form 

 the subject of the next chapter, and are most exhaustively treated. 

 Here the Jacotinga, a micaceous iron-ore, and the Itabirite, a mica- 

 ceous iron-schist, form the principal matrix of the metal, and being 

 almost peculiar to this locality, are distributed, in greater or less 

 quantity, over most of the gold districts. 



The remaining chapters treat of : Notices of Copper Mines near 

 Copiapo, in Chili ; Notices of Gold Mines in Yirginia ; On the 

 Native Copper of Lake Superior ; the Metalliferous Eocks of 

 Gloucester, in New Brunswick ; On the Copper-bearing Sandstone 

 of Huidobro, in Spain ; On the Mines of Chalanches d'Allemont, 

 France ; Notice of the Sark's Hope Mine, Sark ; On the Copper 

 Mines in Ireland ; On the Detrital Gold in Wicklow ; a Notice 

 of the Clogan Gold Mine in North Wales; On the Chrome-ore 

 of Breadalbane ; On the Molybdenite of Tomnadashan, in Perthshire ; 

 On the Caradon District of East Cornwall ; and on the Lead Mines 

 of Menheniot, Lanreath, and Saint Pinnock, in Cornwall. 



The second part contains the Notes on Subterranean Temperatures, 

 by the same author, and numerous plates, illustrating the papers 

 above named ; also voluminous tables, containing a mass of valuable 

 information relating to the mines described. These are accompanied 

 by a most copious Index, occupying 131 pages, which, with the very 

 numerous notes and references, greatly enhance the value and useful- 

 ness of the work. 



It is impossible to gi'v^ in these pages an adequate notion of the 

 minuteness of detail andacuteness of observation which characterize 

 every page of the book ; they must be studied, and thoroughly too, 

 to be properly appreciated by all interested in so very important a 

 subject as the progress and economy of mining. — T. D. 



II. — Eeport of the Commissionees Appointed to Inquire into the 

 Several Matters Eelating to Coal in the United Kingdom. 

 Vol.1. General Eeport and Twenty-two Sub-reports. Folio. 1871. 



IT was in June, 1866, that the now celebrated Coal Commission 

 was appointed. It had for objects — firstly, to investigate tlie 

 probable quantity of coal contained in the Coal-fields of the United 

 Kingdom, and to report on the quantity of such coal which may be 

 reasonably expected to be available for use ; secondly, to ascertain 

 whether it is probable that coal exists at workable depths under the 

 Permian, New Eed Sandstone, and superincumbent strata ; thirdly, 

 to inquire as to the quantity of coal at present consumed in the 

 various branches of manufacture, for steam navigation, and for do- 



