Young Boulton appears to have engaged in business with much spirit. By the time he was seventeen he had introduced several important improvements in the manufacture of buttons, watch-chains, and other trinkets; and he had invented the inlaid steel buckles which shortly after became the fashion. These buckles were exported in large quantities to France, from whence they were brought back to England and sold as the most recent productions of French ingenuity. The elder Boulton, having every confidence in his son’s discretion and judgment, adopted him as a partner so soon as he came of age, and from that time forward he took almost the entire management of the concern. Although in his letters he signed “for father and self,” he always spoke in the first person of matters connected with the business. Thus, in 1757, we find him writing to Timothy Holles, London, as to the prices of “coat-link and vest buttons,” intimating that to lower them would be to beat down price and quality until it became no business at all; “yet,” said he, “as I have put myself to greater expense than anybody else in erecting the best conveniences and the completest tools for the purpose, I am not willing that any interlopers should run away with it.” We find him at the same time carrying on a correspondence with Benjamin Huntsman, of Sheffield, the celebrated inventor of cast-steel.[96] On the 19th January, 1757, he sends Huntsman “a parcel of goods of the newest patterns,” and at the same time orders a quantity of Huntsman’s steel. “When thou hast some of a proper size and quality for me, and an opportunity of sending it, thou may’st, but I should be glad to have it a little tougher than the last.” He concludes--“I hope thy Philosophic Spirit still laboureth within thee, and may it soon bring forth Fruit useful to mankind, but more particularly to thyself, is the sincere wish of Thy Obliged Friend.” With a view to economy, Boulton in course of time erected a steel-house of his own for the purpose of making steel; and he frequently used it to convert the cuttings and scraps of the small iron wares which he manufactured, into ordinary steel, afterwards melting and converting it into cast-steel in the usual way.