188 GEOIOGT. 



known as the ^' Rough Rock," which is the highest memher of the 

 Millstone Grit series, and the fine-grained flagstones which occur in the 

 Lower Coal Measures. The flagstones are also used for roofing. " Cal- 

 liard," or " Gannister," is a hard siliceous rock in the Lower Coal 

 Measures, associated with the Halifax Hard Bed and Halifax Soft Bed 

 (coals) ; beneath the former the Gannister sometimes changes into fire- 

 clay. The chief bed of fire-clay is that beneath the Halifax Hard 

 Coal ; it is 5 1 feet thick. The range, thickness, and character of the 

 Coal-seams are given; and especial notice is taken of the Low-Moor 

 Coal and Ironstone. The water-supply of the district is noticed. 



W. T. 



Bkooks, Major T. B. The Method and Cost of Mining the Red 

 Specular and Magnetic Ores of the Marquette Iron Region of Lake 

 Superior. Trans. Amer. Inst. Min. Eng. vol. i. pp. 193-203. 



The iron-bearing rocks are Huronian, and have been contorted. A 

 section of Lake Superior Mine is given. 



BuBAT, AmiiD^E. Applications de Geologic a TAgriculture. Paris. 



The first chapter is a general description of the physical character 

 and composition of soils, the third is on water, and the fourth on the 

 connexion between geology and agriculture. C. E. De R. 



BuKTHE, P. L. Notice sur les minerais de plomb argentifere de 

 rUtah, et leur traitement metallurgique en 1873. [Argentiferous 

 Lead Ores in Utah, &c.] 37 pp., plate. Ann. d. Mines, ser. 7, 

 vol. V. 

 The rocks in which the lodes are situated are thick beds of grit and 

 two series of dolomites, resting on a fine-grained very regularly bedded 

 granite. The grits have assumed the appearance of quartzites, and the 

 dolomitic limestones are in places coarsely crystalline. The age of the 

 sedimentary rocks is not settled yet, some regarding them as Carbo- 

 niferous, others as Devonian ; they are traversed by several dioritic 

 dykes. The more important lodes occur at the junction of the quartzite 

 grits with the second dolomitic band, but others are found in the 

 granite. G. A. L. 



. Notice sur les gisements des minerais d'argent, leur exploita- 

 tion et leur traitement metallurgique aux Etats-Unis. (Premiere 

 partie.) [Silver Ores in the United States.] 112 pp., 3 plates. 

 Ann. des Mines, ser. 7, vol. v. 

 This part comprises detailed descriptions of the mining districts of 

 Utah and adjoining territories,including the modes of working. The lodes 

 described are those of Comstock, of Austin (Nevada), of Gilpin County 

 and Clear Creek County (Colorado). These lodes are chiefly argenti- 

 ferous : those of Comstock are at the junction of the syenite and green- 

 stone ; those of Colorado are - in granite and gneiss, in more or less 

 vertical positions j while those of Austin he in the granite in more or 

 less horizontal planes. The plates are plans of the workings, showing 



