Another of Mr. Maudslay's inventions was his machine for punching boiler-plates, by which the production of ironwork of many kinds was greatly facilitated. This improvement originated in the contract which he held for some years for supplying the Royal Navy with iron plates for ships' tanks. The operations of shearing and punching had before been very imperfectly done by hand, with great expenditure of labour. To improve the style of the work and lessen the labour, Maudslay invented the machine now in general use, by which the holes punched in the iron plate are exactly equidistant, and the subsequent operation of riveting is greatly facilitated. One of the results of the improved method was the great saving which was at once effected in the cost of preparing the plates to receive the rivets, the price of which was reduced from seven shillings per tank to ninepence. He continued to devote himself to the last to the improvement of the lathe,--in his opinion the master-machine, the life and soul of engine-turning, of which the planing, screw-cutting, and other machines in common use, are but modifications. In one of the early lathes which he contrived and made, the mandrill was nine inches in diameter; it was driven by wheel-gearing like a crane motion, and adapted to different speeds. Some of his friends, on first looking at it, said he was going "too fast;" but he lived to see work projected on so large a scale as to prove that his conceptions were just, and that he had merely anticipated by a few years the mechanical progress of his time. His large removable bar-lathe was a highly important tool of the same kind. It was used to turn surfaces many feet in diameter. While it could be used for boring wheels, or the side-rods of marine engines, it could turn a roller or cylinder twice or three times the diameter of its own centres from the ground-level, and indeed could drive round work of any diameter that would clear the roof of the shop. This was therefore an almost universal tool, capable of very extensive uses. Indeed much of the work now executed by means of special tools, such as the planing or slotting machine, was then done in the lathe, which was used as a cutter-shaping machine, fitted with various appliances according to the work.