190 GEOLOGY. 



surface of the blue clay, and over this bed the higher strata slip. (From 

 abstract in Proc. Inst. Civ. Eng.) 

 GoTT, C. On the Bradford Waterworks. Eep. Brit. Assoc, for 1873, 



pp. 451-458. 

 Some notes are given of the gathering- grounds, and of the relation 

 of the strata and springs to the reservoirs. 



Grosjean, — . Ressources houilleres de la France. [Coal resources 



of France.] Compt. Eend. 2 sess. Assoc. Frang. pp. 364-369. 

 A discussion on the produce and probable duration of French coal. 



Hahn, 0. H., A. EiLEEs, and Dr. R. "W. Eaymond. The Smelting 

 of Argentiferous Lead Ores in Nevada,. Utah, and Montana. 

 Trans. Amer. Inst. Min. Eng. vol. i. p. 91. 



Contains references to materials, ores, &c. 



Haeden, J. W. The Longwall System of Mining. Trans. Amer. 

 Inst. Min. Eng. vol. i. p. 300. 



Refers to the Warwickshire coal-field, pp. 302, 303. 



Haedman-, Edwaed T. On the present State of Coal Mining in the 

 County of Tyrone. Journ. Eoy. Dublin Soc. vol. vi. no. 42, pp. 

 366-383, plate and two woodcuts ; Discussion, pp. 457, 458. 



There are two coal-fields ; the larger, although small, contains 18 

 seams, from 10 inches to 9 feet in thickness, which have been worked, 

 including two of excellent cannel. The lowest seams occur near Dun- 

 gannon, in hard beds, which answers to the Gannister beds of England. 

 The upper series is found around Coal Island, in very soft beds, with 

 thick layers of fire-clay and shales containing clay-ironstone, and there 

 are 10 seams of a yard and upwards in thickness. The coal-field is 

 bounded on the north-west by a large fault, but on the east are Triassic 

 rocks, underneath which the Coal Measures extend. A good deal of 

 the coal has been wrought out ; but there remains a total available 

 supply of between 30 and 40 millions of tons, estimating only coals of 

 a yard and upwards thick, and many of the seams are of good quality. 

 The smaller coal-field at Annaghone, some miles north, has an area of 

 about 250 acres, and contains three coals, two of which, 3 and 9 feet 

 thick, are of good quality. E. T. H. 



Haeeiss-Gasteel, — . Report on the Iron and Steel Industries of the 

 United States. Reports by Her Majesty's Secretaries of Embassy 

 and Legation, Commercial No. 18 (1874), part ii. 8vo. Pp. 

 129-816. 

 Details are given of analyses, production, method, and cost of work- 

 ing, &c. of the chief iron-producing districts. This part of the report 

 (pp. 131 to 198) is divided into the following heads: — Lake Superior 

 region, Missouri region, Lake Champlain region, region of southern 

 ores, Pennsylvania region. Statistics and a general review of ores are 

 appended. W. T. 



Heatheeingtok, A. The Mining Industries of Nova Scotia. Pp. 

 23. London. 



