Thomas Newcomen, a Baptist ironmonger, blacksmith, and locksmith, supplied iron tools to mine workers. He was aware of the problem of flooding of mines and the awkward system of pumps which were used one above the other and were powered by teams of horses. He made a very valuable contribution to power generation by inventing the atmospheric pressure steam engine with piston around 1712. He did this by connecting theory with experiment, through the use of scientific knowledge, especially the Royal Society's investigation into atmospheric pressure. First cold water was poured on a cylinder in which a piston could move up and down. This caused steam inside the cylinder to cool and condense into water. The vacuum created inside the cylinder under the piston caused atmospheric pressure on top of the piston to push the piston down. The piston was attached by a rod to the end of a beam which end then swung down from a point on a vertical stand to which it was attached. When the beam swung, its other end, which was attached to a rod connected to a pump, rose, thus working the pump. Then steam from water heated in a boiler under and communicating with the cylinder was allowed into the cylinder under the piston. This overcame the atmospheric pressure on the piston from above and allowed the piston to rise by a counterweight on the rod over and connecting to the pump. Boys opened and closed the steam valve, which let steam into the cylinder from below, and the water valve, which let cold water pour on the cylinder from above. Then the boys were replaced by the valves being connected to the swinging beam which caused them to open and close at perfectly regular intervals. A story gives the credit for this improvement to an inventive valve boy who wanted to play with his friends. In 1712, the mining industry used this steam engine to pump water out of mine-shafts which had flooded. These engines were also used to supply water to reservoirs' locks at canals, and drinking water facilities in towns. One such engine developed power equivalent to fifty horses working at one sixth the cost. It was the first automatic machine since the clock.
Then James Watt invented the steam engine which used steam as a force acting on the piston. Watt made his living making scientific instruments for Glasgow University. Around 1764, he was fixing one of Newcomen's engines belonging to the university, when he saw its inefficiencies, such as the loss of heat when the cylinder was cooled. He saved this heat energy by having the steam condensed in another vessel distinct but connected to the cylinder. This condenser was kept constantly cool by cold water. So the condensed steam was pumped back into the boiler and it circulated continuously, thus obviating the need for constant resupply of water. In order to avoid the necessity of using water to keep the piston air-tight, and also to prevent the air from cooling the cylinder during the descent of the piston, he used the expansion of the steam to push the piston instead of atmospheric pressure. Then, in order to expand the use of the steam engine beyond that of a pump, he converted the oscillating motion of the beam into rotary motion. He formed a partnership with John Roebuck, who had a two-thirds interest. But when Roebuck needed money, he sold his interest to Matthew Boulton. Boulton wanted better power that that of his watermill for his workshops that made metal buttons, watch chains, shoebuckles of engraved steel, ornamental bronzes, vases, chandeliers, tripods, silver and plated wares, and imitation gold and tortoiseshell work. In dry weather, about eight horses were needed to aid in driving the machinery. A steam pump could pump water from the bottom of the watermill to the top to be used again. He had built up this factory of five buildings and six hundred workers, with 9,000 pounds derived from his marriage to an heiress. By 1774, the partnership had built a model steam engine with rotary power whose design could be sold. The price of the engine was set as the amount of money saved on fuel costs in the first three years of its operation. This machine was a relatively economical user of energy, capable of performing almost any kind of work.
About 1750, John Wilkinson, the son of a farmer who also oversaw an iron furnace, substituted mineral coal for wood charcoal in the smelting and puddling of iron ore. In 1766, he made it possible to transport coal out of mines on rail wagons drawn by horses. As father of the iron industry, he made iron chairs, vats for breweries and distilleries, and iron pipes of all sizes. With his invention of the first precision boring machine, he provided Watt with metal cylinders of perfectly accurate shape, which were necessary for the smooth working of Watt's steam engine. In 1775 he bought a pumping steam engine from Boulton and Watt's company for his ironworks. It pumped three times as fast as Newcomen's engine.
Watt's steam engine came to be used for power-loom weaving and then for all sorts of manufactures. It would put England ahead of every manufacturing country in the world. Millwrights built, installed, and later designed not only steam engines but the machinery that they drove. These men were essential in setting up the first factories. They were the most imaginative and resourceful craftsmen. They knew how to use a turner's, a carpenter's and a blacksmith's tools and had supervised or done smith work, brick-laying or stone-mason's work in erecting and maintaining windmills with their many gears and bearings. There was a good deal of variety in mills, as well as in the structure and workmanship of them, some being worked by horses, some by wind, and others by water. They had some knowledge of arithmetic and practical mechanics. They could draw out a plan and calculate the speed and power of a wheel. Although technically in a branch of carpentry, the millwrights learned to work with metal as well. Metal was superior to wood not only because of its strength but because wood parts were irregular in motion and wore out rapidly. So iron and brass parts came to replace wood and leather parts.
In 1728, J. Paine got a patent for rolling iron instead of hammering it. The iron bars, being heated in a long hot arch or cavern passed between two large metal rollers, which had certain notches or furrows on their surfaces.
Clockmaker and Quaker Benjamin Huntsman was struck with the difficulty of finding finely tempered steel for the springs of his watches and pendulums of his clocks. He experimented for years to find a homogeneous and flawless metal, and finally, in 1740, invented cast steel, which had high tensile strength and was much harder than ordinary steel. He did this by remelting refined high quality wrought iron bars at very high temperatures in sealed fireclay crucibles, together with small quantities of charcoal and ground glass as reagents. This distributed the carbon evenly in the metal, which hammering could not do. He approached the Sheffield cutlers, who finally agreed to try his cast steel for fear of losing their business to some other manufacturers who were approaching Huntsman. Since Huntsman had no patent, he worked at night and employed only men who would keep his secret. His steel was made at night. His factory became prosperous about 1770 and the excellence of his steel manufacture was never equaled. Steel and wrought iron was scarce and expensive.
Around 1748, iron founder Samuel Walker, discovered Huntsman's secret by appearing at Huntsman's factory disguised as a shivering tramp who asked to warm himself by the furnace fire. He feigned sleep while watching the whole process. When he began to make cast steel, his annual output grew from 900 pounds in 1747 to 11,000 pounds in 1760 and he made a fortune.
Silver was plated over copper from 1751. White metal from tin and antimony was used from about 1770.
The brass industry was beginning to produce brass from copper and zinc that was as good as foreign brass. The secret of plate-glass manufacture came to England in the 1770s.
In 1773, a corporation was set up for the manufacture of plate glass. It could raise joint-stock because of the great risk and large expense of the undertaking.