The important results of Watt's labours having happily at this time become more publicly known, Mr. Matthew Boulton, whose establishment at Soho, near Birmingham, was at that time the most complete manufactory for metal-work in England, and conducted with unexampled enterprise and spirit, proposed to purchase Dr. Roebuck's interest in the patent. This arrangement was effected in the year 1773, and in the following year Mr. Watt removed to Soho, where a portion of the establishment was allotted to him, for the erection of a foundery, and other works necessary to realise his inventions on a grand scale. The patent which had been granted in 1769 was limited to a period of fourteen years, and would consequently expire about the year 1783. From the small progress which had hitherto been made in the construction of engines upon the new principle, and from the many difficulties still to be encountered, and the large expenditure of capital which must obviously be incurred before any return could be obtained, it was apparent that unless an extension of the patent right could be obtained, Boulton and Watt could never expect any advantage adequate to the risk of their great [Pg132] enterprise. In the year 1774 an application was accordingly made to parliament for an extension of the patent, which was supported by the testimony of Dr. Roebuck, Mr. Boulton, and others, as to the merits and probable utility of the invention. An Act was accordingly passed, in 1775, extending the term of the patent until the year 1800. (75.) The following abstract of this Act may not be uninteresting at this time, when the anticipations expressed in it have been so successfully and extensively realised:— "An Act for vesting in James Watt, engineer, his executors, administrators, and assigns, the sole use and property of certain steam engines, commonly called fire engines, of his invention, throughout his majesty's dominions, for a limited time: "And whereas the said James Watt hath employed many years, and a considerable part of his fortune, in making experiments upon steam engines, commonly called fire engines, with a view to improve those very useful machines, by which several very considerable advantages over the common steam engines are acquired; but upon account of the many difficulties which always arise in the execution of such large and complex machines, and of the long time requisite to make the necessary trials, he could not complete his intention before the end of the year 1774, when he finished some large engines as specimens of his construction, which have succeeded, so as to demonstrate the utility of the said invention: