The principles of reduction by the old style furnaces and methods we have described have been revived and combined with improvements. For instance, the old Catalan style of furnace has been retained to smelt the iron, but in one method the iron is withdrawn before it is reduced completely and introduced into another furnace, where, mixed with further reducing ingredients, a better result by far is produced with less labour. It would be a long list that would name the modern discoverers and inventors of the century in the manufacture of iron and steel. But eminent in the list, in addition to Davy and Bessemer, and others already mentioned, are Mushet, Sir L. Bell, Percy, Blomfield, Beasley, Giers and Snellus of England; Martin, Chennot, Du Motay, Pernot and Gruner of France; Lohage, Dr. C. L. Siemens and Höpfer of Germany; Prof Sarnstrom and Akerman of Sweden; Turner of Austria; and Holley, Slade, Blair, Jones, Sellers, Clapp, Griffiths and Eames of the United States. Some of the new metals discovered in the last century have in this century been combined with iron to make harder steel. Thus we have nickel, chromium, and tungsten steel. Processes for hardening steel, as the “Harveyized” steel, have given rise to a contest between “irresistible” projectiles and “impenetrable” armour plate. If there are some who regard modern discoveries and inventions in iron and steel as lessening the number of workmen and cheapening the product too much, thus causing trouble due to labour-saving machinery, let them glance, among other great works in the world, at Krupp’s at Essen, where on January 1st, 1899, 41,750 persons were employed, and at which works during the previous year 1,199,610 tons of coal and coke were consumed, or about 4000 tons daily. Workers in iron will not be out of employment in the United States, where 16,000,000 tons of coke are produced annually, 196,405,953 tons of coal mined, 11,000,000 tons of pig iron and about 9,000,000 tons of steel made. The increase of population within the last hundred years bears no comparison with this enormous increase in iron and fuel. It shows that as inventions multiply, so does the demand for their better and cheaper products increase. As the other metals, gold, silver, copper and lead often occur together, and in the same deposits with iron, the same general modes of treatment to extract them are often applied. These are known as the dry and the wet methods, and electro-reduction.