A very few words of explanation will serve to illustrate the importance of Maudslay's invention. Every person is familiar with the uses of the common turning-lathe. It is a favourite machine with amateur mechanics, and its employment is indispensable for the execution of all kinds of rounded work in wood and metal. Perhaps there is no contrivance by which the skill of the handicraftsman has been more effectually aided than by this machine. Its origin is lost in the shades of antiquity. Its most ancient form was probably the potter's wheel, from which it advanced, by successive improvements, to its present highly improved form. It was found that, by whatever means a substance capable of being cut could be made to revolve with a circular motion round a fixed right line as a centre, a cutting tool applied to its surface would remove the inequalities so that any part of such surface should be equidistant from that centre. Such is the fundamental idea of the ordinary turning-lathe. The ingenuity and experience of mechanics working such an instrument enabled them to add many improvements to it; until the skilful artisan at length produced not merely circular turning of the most beautiful and accurate description, but exquisite figure-work, and complicated geometrical designs, depending upon the cycloidal and eccentric movements which were from time to time added to the machine. The artisans of the Middle Ages were very skilful in the use of the lathe, and turned out much beautiful screen and stall work, still to be seen in our cathedrals, as well as twisted and swash-work for the balusters of staircases and other ornamental purposes. English mechanics seem early to have distinguished themselves as improvers of the lathe; and in Moxon's 'Treatise on Turning,' published in 1680, we find Mr. Thomas Oldfield, at the sign of the Flower-de-Luce, near the Savoy in the Strand, named as an excellent maker of oval-engines and swash-engines, showing that such machines were then in some demand. The French writer Plumier[3] also mentions an ingenious modification of the lathe by means of which any kind of reticulated form could be given to the work; and, from it's being employed to ornament the handles of knives, it was called by him the "Machine a manche de Couteau d'Angleterre." But the French artisans were at that time much better skilled than the English in the use of tools, and it is most probable that we owe to the Flemish and French Protestant workmen who flocked into England in such large numbers during the religious persecutions of the sixteenth and seventeenth centuries, the improvement, if not the introduction, of the art of turning, as well as many other arts hereafter to be referred to. It is certain that at the period to which we refer numerous treatises were published in France on the art of turning, some of them of a most elaborate character. Such were the works of De la Hire,[4] who described how every kind of polygon might