pass daily above the very ground where his colliers work."

In the year 1755 Whitehaven lost both Sir James Lowther and Carlisle Spedding. The latter, after conducting the collieries with wonderful ability and energy during the long period of thirty-seven years, had the misfortune to fall a victim to the fire-damp, to disarm which he had laboured so diligently. He was killed by an explosion in the above year, while underground discharging his duties in the mines.

Within a few years after the death of Carlisle Spedding, a great improvement in the method of ventilating coal-mines was introduced by his son, James Spedding, who succeeded to the management of the collieries belonging to the Lowther family on the death of his father. The elder Spedding, in common with his contemporaries, directed the ventilating current specially towards such parts of the mines as were in course of being worked, to the neglect of the portions already excavated and abandoned. This early system of ventilating is termed face airing, on account of the air being carried along the front or "face" of the solid coal, where the miners were immediately at work. It was open to the fatal objection that many vacant unventilated spaces were left, in which the noxious gases unobserved and unsuspected might

". . . . train their dread artillery,"

ready, under altered conditions of the atmospheric pressure, to steal out upon the miners' lights and in an instant carry death and destruction through the colliery.

The improved system, first introduced about 1760 in a colliery at Workington (where were situated some recently opened mines belonging to the Lowther family), consisted in forming the whole of the excavated part of the mine into one vast labyrinth, or pipe, by means of doors and stoppings, thus compelling the ventilating current to sweep through every passage of the mine on its way between the downcast and upcast pits. This system is technically termed coursing the air.

Possibly James Spedding may have been incited to set about improving the ventilation of collieries from the fact that the steel mill was already ascertained to be not altogether safe to work with. Previous to 1765 it was known at Whitehaven to have been the cause of several explosions; but it continued to be extensively used long afterwards, many being quite unaware of the danger connected with it.

CHAPTER XI.

REVIVAL OF THE IRON TRADE. GREAT BUILDING OF STEAM-ENGINES IN THE NORTH OF ENGLAND. -INCREASING DEPTH OF THE PITS.-VARIOUS APPLIANCES FOR VENTILATING THE MINES.-EXPLOSIONS OF FREQUENT OCCURRENCE.

IN the early half of the eighteenth century the iron trade of Britain was at an extremely low ebb. The charcoal iron manufacture was fast dying out for want of fuel; the manufacture of iron with coke or coal was yet only in its infancy. The total make of pig-iron in England in 1740 is set down at 17,350 tons.

It is generally agreed that the first notable revival of the iron trade took place at Coalbrookdale Foundry, in Shropshire, but a considerable discrepancy prevails as to the precise date when charcoal was superseded by coal fuel in the smelting operations. It appears that the manufacture of iron with coal (or coke) commenced here in the time of the first Abraham

Darby, who settled at Coalbrookdale in 1709 and died in 1717. Charcoal was employed in the blast furnace when Darby first began operations, but soon afterwards coke was used-according to Scrivenor in 1713-the fuel employed in smelting a charge of ore consisting of five baskets of coke, two of brays or small coke, and one of peat. The quantity of iron produced at this period, however, was insignificant, only reaching from five to ten tons per week, and it was not until long subsequently that the production of pit-coal iron at Coalbrookdale assumed any importance. The second period appears to date from 1730-5, about which time a more powerful blast was obtained by the erection of a Newcomen steam-engine to provide an increased supply of water for driving the blast water-wheel.

For a long period Coalbrookdale Foundry continued one of the principal seats of the pit-coal iron industry, but the success achieved here led to the establishment of many new iron-works in different parts of the kingdom for the manufacture of iron by the same process. The greater abundance and cheapness of iron which ensued led to a rapid extension of its use.

Not only were the Coalbrookdale Company the first to manufacture iron with coal on a large scale, but they took the lead in promoting the more general use of cast-iron as a substitute for wood and other

materials. It being contrary to the principles of the Darbys, as members of the Society of Friends, to accept contracts, however lucrative, for the manufacture of engines of war, this firm developed the application of iron in the arts of peace. Hence, while the proprietors of the great foundry at Carron became celebrated for their Carronades or "smashers," the Coalbrookdale firm are famous as the constructors of the first iron railways and the builders of the first iron bridge; and their foundry became the great emporium for cast-iron cylinders for steamengines, cast-iron pipes for mine-pumps, and useful articles of all descriptions made of the same material.

About the year 1740 a commencement had already been made to use cast-iron cylinders in steam-engines (all the earlier cylinders having been made of brass), and there is little doubt that the facility with which large iron cylinders could from this time be obtained helped on to a great extent the marked increase in the building of steam-engines which took place shortly after the middle of the eighteenth century.

Prominent among the builders of engines, as well as in promoting other improvements in the mechanical engineering of collieries in the Newcastle-onTyne district at this period, was William Brown, an eminent colliery viewer. Brown was brought up at Throckley, a village situated about six miles west of Newcastle, and was of an aspiring mind and endowed