year, he erected one of his improved engines, which he had brought from Scotland; and, after full proof of its utility, obtained from parliament in 1775 a prolongation of the term of his patent for 25 years from that date. He then entered into partnership with Mr. Boulton, and established a very extensive manufactory of these engines at Soho, whence most of the great mines and manufactories of England are supplied, they being now applied to almost every mechanical purpose where great power is requisite.
The application of this improved steam-engine at Soho to raise and return the water, extended the powers of the water-mill; which induced Mr. Boulton to rebuild it a second time upon a much larger scale, and several engines were afterwards erected at Soho for other purposes, by which the manufactory was greatly extended, the source of mechanical power being thus unlimited.
Amongst the various applications of the steam-engine, that of coining seems to be of considerable importance, as by its powers all the operations are concentered on the same spot; such as rolling the cakes of copper hot into sheets; 2dly, fine rolling the same cold in steel polished rollers; 3dly, cutting out blank pieces of coin, which is done with greater ease and rapidity by girls than could possibly be done by strong men; 4thly, the steam-engine also performs other operations, such as shaking the coin in bags; and 5thly, it works a number of coining machines, with greater rapidity and exactness, by a few boys of twelve to fourteen years of age, than could be done by a great number of strong men, without endangering their fingers, as the machine itself lays the blanks upon the die perfectly concentral with it, and when struck displaces one piece and replaces another.
The coining mill, which was erected in 1788, and has since been greatly improved, is adapted to work eight machines, and each is capable of striking from seventy to eighty-four pieces of money per minute, the size of a guinea, which is equal to between 30,000 and 40,000 per hour; and at the same blow which strikes the two faces the edge of the piece is also struck, either plain or with as inscription upon it, and thus every piece becomes perfectly round, and of equal diameter; which is not the case with any other national money ever put into circulation.
Such a coining mill, erected in the national mint, would, in cases of emergency, be able to coin all the bullion in the Bank of England at a short notice, without the necessity of putting dollars, or any other foreign coin into circulation; and by erecting double the number of presses a double quantity may be coined.
Dr. Darwin, in a more recent compliment paid to Soho than his letter above printed, says, after a short description of this mint, that the whole of this magnificent and expensive apparatus moves “with such superior excellence and cheapness of workmanship, as well as with works of such powerful machinery, as must totally prevent clandestine imitation, and in consequence save many lives from the hand of the executioner; a circumstance worthy the attention of a great minister. If a civic crown was given in Rome for preserving the life of one citizen, Mr. Boulton should be covered with garlands of oak.”
It is worthy observation, that the ground of the silver money coined by this machine has a much finer and blacker polish than the money coined by the common apparatus.
In consequence of Mr. Boulton’s money being perfectly round, and of equal diameter, he proposed the following coincidence between money, weights, and measures, in the copper coin, part of which he hath lately executed for the British govern-