DERBYSHIRE. This county is rich in mineral strata. The coal-measures underlie the magncsian limestone, and crop out from beneath it on the west. These coal measures form part of that important coal field which occupies a considerable part of the west riding of Yorkshire, and extends into Nottingham shire and Derbyshire, being bounded on the east by the magnesian limestone, and on the south by the red marl. The strata range from north to south, and dip to the east. The Derbyshire portion of this coal field is east of a lino drawn from between Hathersage and Sheffield to Little Eaton, near Derby. Every variety of coal seems to be found in this field, hard stone coal, cannel, peacock, and caking coal. The coal-pits in Derbyshire are dis persed over the coal field, and are very nu merous, especially about Chesterfield and Alfreton, and in the district south and west of the Cromford and Erewash canals. The beds which lie between the seams of coal are worked for various purposes. The workings of the ironstone are generally begun at the surface, and pursued until they become dan gerous from the loose nature of the stratum in which they lie. The ironstone which is marked with impressions of mussel shells (called the mussel band) is worked as an ornamental marble. From the gritstone beds are quarried grindstones for cutlers; the binds, where they are hard and black, are used as black chalk; others, when decom posed, make good brick earth ; the chinch is sometimes of that kind which is used for fire bricks ; where it crops out to the surface it becomes soft clay. Potter's clay, of various colours and qualities, occurs in this coal field.
Black marble is quarried for ornamental purposes. One of the beds of limestone con tains white chert or china stone, which is ex tensively used in the Staffordshire potteries. The beautiful fluor spar called 'Blue John,' from which vases and other ornaments are made, is found in a mountain of limestone. Numerous veins of lead, zinc, iron, manga nese and copper, also occur.
A large proportion of the land of this county is in permanent pastures, of which some are very rich. Derbyshire cheese is noted as of good quality, and the best is often sold for Cheshire or Gloucester when made of the shape and colour of these cheeses.
The common Derbyshire cheese is not gene rally coloured ; it resembles some kinds of Dutch cheeses, and keeps well.
At Cromford, in this county, the late Sir Richard Arkwright erected a spacious cotton:, mill on the left bank of the Derwent ; it is now occupied by the Messrs. Arkwright, his grandsons, who employ iu these mills and those at Masson, a little higher up the Der went, several hundred persons. Lead mines are worked in the neighbourhood ; lapis cala minaris is ground and prepared, and red lead. manufactured. At Dronfield manufactures are carried on in iron goods, such as railway wheels, cast iron chains and nails, axes, chisels, and other edge tools, and agricultural implements. At Heauor are manufactories for cotton goods, hosiery, and bobbin-net lace. In and near Ashford there are extensive mar ble works where the black and coloured marbles which are quarried in the neighbour hood are wrought into chimney pieces, tables, slabs, &c ; there are also quarries of lime stone; and lead mines. Scythes and reaping hooks are largely manufactured at Beighton and at Hackington. At Clay Cross and in its immediate vicinity are extensive collieries and iron works. At Codnor the Butterly Iron Company have extensive iron works and col lieries; and iron, lead, limestone, and coal are abundant. At Long Eaton, paper mills and stone quarries give employment to many of the inhabitants. Needles, pins, edgetools and mill stones are manufactured at Hather sage. Ironville is a busy and populous dis trict; the inhabitants are employed in the iron works, smelting, &c.; a national school (in which divine service is performed on Sun days) was erected in 1841, at a cost of 3000/., by the Butterly Iron Company, and an infant school has been since erected by the same company ; there is also a mechanics institute. At Milford, six miles from Derby, schools have been founded by the Messrs Strutt, who have extensive cotton and bleaching works here, employing 1,000 bands ; they have also an iron foundry here, in which all their machinery is cast and made, and gas works at Milford which supply the town of Belper.