By these simple, old-fashioned methods he built up a business and accumulated a fortune too large to be thus administered. It would have been impossible for one head to carry the details of work and management, for one pair of eyes to superintend each part of the work, or for one pair of feet, however tireless, to travel all the ways which lead to and from a great modern industrial establishment. Still less could financial direction and protection be compassed by the simple scheme which Mr. Cooper, in his old age, recalled with pride. "I used," he said once, "to pay all my debts every Saturday night; and I knew that what I had left was my own!" This could not have been strictly true; but it doubtless expressed an old man's memory of the way he began, and the principles he had followed, with that horror of debt which dated from the time when debtors could be put in jail. Fortunately for Mr. Cooper, his son Edward, and his son-in-law, Abram S. Hewitt, were at hand to undertake the management of his business enterprises at the time when his own simple methods would have proved inadequate, so that his inventive genius, adventurous courage, and, above all, intense philanthropy, were backed with ample means. In this account of his business ventures (though of much later date than those already mentioned) the part played by Peter Cooper in the development of the American iron industry and in the construction of the first transatlantic submarine telegraph may be recorded. The manufacture of iron was one of the early industries of the American colonies, and after the Revolution it was prosecuted with increased activity in small and primitive establishments. With its development into scientific forms on a large scale Mr. Cooper was both directly and indirectly connected. His Ringwood estate in New Jersey had been the scene of the operations of the Ringwood Company in 1740, and of its successors,--Hasenclever (1764) and Erskine (1771); and the Durham furnace, on the Delaware River in Pennsylvania (on the site of the Durham Iron Works of Cooper & Hewitt), made its first blast in 1727. Mr. Cooper himself was engaged in 1830 in the manufacture of charcoal iron near Baltimore, and in 1836, together with his brother Thomas, he operated a rolling-mill in New York (on Thirty-Third Street, near Third Avenue). At this mill anthracite was used for puddling in 1840. In 1845 the business was removed to Trenton, N. J.; and in the new rolling-mill--then the largest in the United States--built at Trenton for the manufacture of rails, the first iron beams for buildings were rolled in 1854. By the erection of blast furnaces at Phillipsburg and Ringwood, N. J., and Durham, Pa., and the addition of wire mills, bridge shop, chain shop, etc., to the works at Trenton, the purchase of iron and coal lands, and the development of numerous mines, the firm of Cooper & Hewitt achieved high rank among the ironmasters of America; and