Taken from The History, Topography, and Directory of the County Palatine of Durham by Francis Whellan. Second edition published in 1894.

A valuable amount of light may be thrown upon the character of a coal district by surface researches, unaccompanied by the breaking of the ground. Quarries, roads, protruding rocks, sea cliffs, ploughed fields and watercourses, will all yield to an experienced eye their quantum of information, and good facts may be gleaned in the channels and banks of the brooks, which have cut their way down to the harder rock. In the north of England, as well as in other parts of the country, there are frequent opportunities of thus obtaining a measurable profile of some of the lower Coal Measures.

The ordinary mode of boring through the alternating rocks overlaying or forming a coalfield is by means of a steeled chisel, or bit of various form, screwed to rods of best bar iron, about an inch thick, screw-jointed at intervals of from 6 to 18 feet. At the spot selected for the bore-hole, it is usual either to erect a wooden staging or to a shaft to a few feet or yards in depth; sometimes shear legs with sheave are added, so that a greater length of rods may be drawn or lowered by the aid of a windlass. A rotary motion is given to the rods at each stroke by means of a crossbar. The chisel thus at each blow cuts the ground in a fresh position; and when this action has been continued long enough, the rods are withdrawn, by unscrewing length after length, and the "sludger," an iron tube of 6 feet long, with a valve in the bottom, is lowered by a rope, and being dropped heavily several times, soon gets filled with the debris, which being brought up are carefully examined, whilst the rods are again lowered and the pounding continued.

Exploring bore-holes are gene rally from to inches diameter, and are often, to guard against accidents, lined with pipes of sheet iron. Greater diameters are employed when depths of over 300 feet are attained, and steam power with improved appliances has been largely employed of late years. The tariff for boring at Newcastle was in 1854

irrespective of charges for carriage, fixing apparatus, and boring through rocks of unusual hardness, &c. For deeper bore-holes, i.e., from 1000 to 2000 feet, it is difficult to give an approximate idea of the cost, but thousands of pounds are soon involved, and cases might be named where the cost has been at the end no less than and even Ј12 per foot! Diamonds set in a steel ring have been largely used of late for boring to depths of 500 to 2000 feet. The actual sinking, when in ordinary Coal Measures, is effected by the heavy pick, called a hack, by hammers and wedges, and by blasting with powder, whilst the broken ground is raised to the surface by a windlass or jack-roll; then as the work gets deeper, by a gin or horse-whin, and afterwards by a steam-engine, to be replaced when the pit is down by the regular winding-engine.

But when the measures are covered by other and more absorbent strata, the winning of a colliery becomes a most serious undertaking, tasking the energies of the best men, and sometimes collapsing after a ruinous outlay.

The preparatory work of a colliery is far from being completed when the shaft has reached the bottom of the seam. It would be ruin to attempt at once to extract coal in any quantity, especially in deep workings, for the weakening of the ground by its removal would not only rend to bring in or destroy the pit, but would crush the roads, which should remain open for the working of the distant parts of the "royalty" or field of operations. A large mass of coal has to be left unwrought round the pit as shaft-pillar, with narrow drifts, cut through it, to serve as roads and as channels for air and water. Next, the levels are driven out in the directions required by the position of the strata.

When in the early periods of coal-mining the works extended but a short distance from the shafts, and only small quantities of mineral were extracted, it used - as in many small works of the present day – to be conveyed by dragging in sleds or sledges along the somewhat slippery floor of the scam. In some districts the ruder method of carrying in baskets was practised, and this toilsome work ceased to be performed. by women "bearers" in Scotland only in 1843. In other pits, barrows were employed, the wheel running on a plank called the barrow-way.