58 Mr, Sopwith on the [March 9, 



at Alston, at 3*62 feet above the surface, is 956 '80 feet above sea 

 level. The highest summit of tliis range of mountains is, at Cross- 

 fell, about 2900 feet. The detailed section of strata and mines at 

 Allenheads represents a tract of country varying from 1400 feet to 

 2200 feet. The meteorological conditions of different parts of the 

 district consequently vary considerably; and a diagram, prepared 

 by Mr. Bewick, illustrated the exact range of observations of 

 barometer, thermometers, and rain guage, during the months of 

 December 1854 and January 1855. The position of the strata, as 

 regards facilities for mining, is mainly dependent on the elevation 

 of the country. This was illustrated by a model, made in separate 

 moveable parts, showing the coal measures, millstone grit, and 

 mountain limestone formations, and representing, first, the condition 

 of the several rocks previous to being dislocated by a fault ; 

 secondly, the effects of such a fault, or break of the strata, by which 

 on one side the strata are depressed ; and thirdly, the subsequent 

 results of denudation, or wearing away of the surface by water. 

 The direction of the great Tynedale fault was shown on the large 

 map, and the amount of depression varies from 500 to 1000 feet. 



The situation of the principal coal-fields of the North of England 

 was also described, as also the several harbours, of the number and 

 extensive improvements of which various details were given, and some 

 of the chief circumstances connected with the working of coal 

 mines, of which several diagrams were exhibited. From the river 

 Coquet to the Tees, the coal-fields of Northumberland and Durham 

 extend along the coast a distance of about 50 miles : the extreme 

 breadth is nearly 25 miles, and the average breadth about 16 miles ; 

 the total area from 700 to 800 miles. The entire series of coal 

 seams or beds, by no means extend over so large a space, and 

 different qualities of coal abound in separate portions of the district. 



The application of cages, introduced by Mr. T. Y. Hall, effected 

 great economy in the methods of bringing coal to the surface. The 

 several coal seams, and the accompanying beds of silicious and other 

 strata, as found at Townley colliery, were shown by a large section and 

 drawing which had been expressly prepared for the purpose of illus- 

 trating, on a large scale, the general outline of colliery workings, by 

 Mr. J. B. Simpson, son of the viewer of that colliery, and it fur- 

 nished, at the same time, an excellent specimen of delineation of 

 such objects. 



Open spaces in the midst of the plan showed what is locally 

 termed the broken or waste, being the excavated coal wholly re- 

 moved ; but the greater part of the diagram was occupied with a 

 representation of the preliminary operations which, in the first 

 instance, constitute the ordinary workings of a coal mine or 

 colliery. 



Access to the coal is obtained by means of vertical shafts. One 

 of these is the downcast shaft, the other the upcast shaft, which 

 names are derived from the important use of these shafts in ven- 



