In 1806 the manufacture of iron was begun, and by 1825 this had become the leading industry. Among the earlier prominent iron industries was the Kensington Iron Works, of which Samuel Church (born February 5, 1800; died December 7, 1857), whose family has been resident in Pittsburgh from 1822 to the present day, was the leading partner. In the manufacture of iron and steel products Pittsburgh ranks first among the cities of the United States, their value in 1905 amounting to $92,939,860, or 53.3 per cent. of the total of the whole country. Several towns in the near neighborhood are also extensively engaged in the same industry, and in 1902 Allegheny County produced about 24 per cent. of the pig iron; nearly 34 per cent. of the Bessemer steel; 44 per cent. of the open hearth steel; 53 per cent. of the crucible steel; 24 per cent. of the steel rails, and 59 per cent. of the structural shapes that were made that year in the United States. In 1905 the value of Pittsburgh's foundry and machine-shop products amounted to $9,631,514; of the product of steam railroad repair shops, $3,726,990; of malt liquors, $3,166,829; of slaughtering and meat-packing products, $2,732,027; of cigars and cigarettes, $2,297,228; of glass, $2,130,540; and of tin and terne plate, $1,645,570. Electrical machinery, apparatus, and supplies were manufactured largely in the city, to a value in 1905 of $1,796,557. The Heinz Company has its main pickle plant in Pittsburgh, the largest establishment of its kind in the world. Pittsburgh's first glass works was built in 1797 by James O'Hara. In 1900, and for a long period preceding, the town ranked first among American cities in the manufacture of glass, but in 1905 it was outranked in this industry by Muncie, Indiana, Millville, New Jersey, and Washington, Pennsylvania; but in the district outside of the limits of Pittsburgh much glass is manufactured, so that the Pittsburgh glass district is still the greatest in the country. In Pittsburgh or its immediate vicinity the more important plants of the United States Steel Corporation are located, including the Carnegie Works at Homestead. Just outside the limits also are the plants of the Westinghouse Company for the manufacture of electrical apparatus, of air-brakes which George Westinghouse invented in 1868, and of devices for railway signals which he also invented.