This machine enlarged at one bound the whole scale of working in iron, and permitted Maudsley's lathe to develop its entire range of capacity. The old 'tilt-hammer' was so constructed that the more voluminous the material submitted to it, the less was the power attainable; so that as soon as certain dimensions had been exceeded, the hammer became utterly useless.
a, a, a, tuyères; b, air-space; c, melted metal
A very important development of the manufacture of steel followed the introduction of the 'Bessemer process,' by means of which a low carbon or mild cast-steel can be produced at about one-tenth of the cost of crucible steel. It is used for rails, for the tires of the wheels of railway carriages, for ship-plates, boiler-plates, for shafting, and a multitude of constructional and other purposes to which only wrought iron was formerly applied, besides many for which no metal at all was used.
Sir Henry Bessemer says: 'It is this new material, so much stronger and tougher than common iron, that now builds our ships of war and our mercantile marine. Steel forms their boilers, their propeller shafts, their hulls, their masts and spars, their standing rigging, their cable chains and anchors, and also their guns and armour-plating. This new material has covered with a network of steel rails the surface of every country in Europe, and in America alone there are no less than 175,000 miles of Bessemer steel rails.' These steel rails last six times longer than if laid of iron.'
Wedgwood at Work
He was bound apprentice to his brother Thomas in 1744, when in his fourteenth year; but this weak knee, which hampered him so much, proved a blessing in disguise, for it sent him from the thrower's place to the moulder's board, where he improved the ware, his first effort being an ornamental teapot made of the ochreous clay of the district.
Wedgwood's copy of the Barberini or Portland Vase was a great triumph of his art. This vase, which had contained the ashes of the Roman Emperor Alexander Severus and his mother, was of dark-blue glass, with white enamel figures. It now stands in the medal room of the British Museum alongside a model by Wedgwood. It stands 10 inches high, and is the finest specimen of an ancient cameo cut-glass vase known. It was smashed by a madman in 1845, but was afterwards skilfully repaired. Wedgwood made fifty copies in fine earthenware, which were originally sold at 25 guineas each. One of these now fetches £200. The vase itself once changed hands for eighteen hundred guineas, and a copy fetched two hundred and fifteen guineas in 1892.
It was in 1751 that Dr Wall, a chemist and artist, completed his experiment in the combination of various elements, and produced a porcelain which was more like the true or natural Chinese porcelain than any ever devised. This was the more remarkable because kaolin had not then been discovered in this country.