The more that the remaining ironmasters became straitened for want of wood, the more they were compelled to resort to cinders and coke made from coal as a substitute. And it was found that under certain circumstances this fuel answered the purpose almost as well as charcoal of wood. The coke was made by burning the coal in heaps in the open air, and it was usually mixed with coal and peat in the process of smelting the ore. Coal by itself was used by the country smiths for forging whenever they could procure it for their smithy fires; and in the midland counties they had it brought to them, sometimes from great distances, slung in bags across horses' backs,--for the state of the roads was then so execrable as not to admit of its being led for any considerable distance in carts. At length we arrive at a period when coal seems to have come into general use, and when necessity led to its regular employment both in smelting the ore and in manufacturing the metal. And this brings us to the establishment of the Coalbrookdale works, where the smelting of iron by means of coke and coal was first adopted on a large scale as the regular method of manufacture. Abraham Darby, the first of a succession of iron manufacturers who bore the same name, was the son of a farmer residing at Wrensnest, near Dudley. He served an apprenticeship to a maker of malt-kilns near Birmingham, after which he married and removed to Bristol in 1700, to begin business on his own account. Industry is of all politics and religions: thus Dudley was a Royalist and a Churchman, Yarranton was a Parliamentarian and a Presbyterian, and Abraham Darby was a Quaker. At Bristol he was joined by three partners of the same persuasion, who provided the necessary capital to enable him to set up works at Baptist Mills, near that city, where he carried on the business of malt-mill making, to which he afterwards added brass and iron founding. At that period cast-iron pots were in very general use, forming the principal cooking utensils of the working class. The art of casting had, however, made such small progress in England that the pots were for the most part imported from abroad. Darby resolved, if possible, to enter upon this lucrative branch of manufacture; and he proceeded to make a number of experiments in pot-making. Like others who had preceded him, he made his first moulds of clay; but they cracked and burst, and one trial failed after another. He then determined to find out the true method of manufacturing the pots, by travelling into the country from whence the best were imported, in order to master the grand secret of the trade. With this object he went over to Holland in the year 1706, and after diligent inquiry he ascertained that the only sure method of casting "Hilton ware," as such castings were then called, was in moulds of fine dry sand. This was the whole secret.