the top of a cylinder, with the concave side downwards. Consequently, when the water was pumped into the cylinder, it immediately forced its way between the bent edges of the collar; and the greater the pressure of water, the tighter became the hold which the collar took of the solid piston. It appears from the testimony of Mr. James Nasmyth, that Bramah was indebted for this simple but beautiful contrivance, to Henry Maudslay, who was at that time a workman in his shop, and who had already greatly assisted him in the construction of his lock. Bramah continued his useful labours as an inventor for many years, and his studies of the principles of Hydraulics, in the course of his invention of the press, enabled him to introduce many valuable improvements in pumping machinery. By varying the form of the piston and cylinder, he was enabled to obtain a rotary motion, which he adopted in the well-known fire-engine. In 1797 he took out a patent for the beer-machine, now in such general use in public houses, and in the description of this he includes a mode of converting every cask in a cellar into a force pump, so as to raise the liquor to any part of the house; a filtering machine; a method of making pipes; a vent peg, and a new form of stop-cock. Bramah also turned his attention to the improvement of the steam-engine, but in this, Watt's patent had left little room for other inventors: and hence Bramah seems to have entertained a grudge against Watt, which was shown strongly in the evidence given by him in the case of Boulton and Watt _versus_ Hornblower and Maberly, tried in December 1796. On the expiry, however, of Boulton and Watt's patent, Bramah introduced several valuable improvements in the details of the condensing engine, the most important of which was his "four-way cock," which was so contrived as to revolve continuously instead of alternately, thus insuring greater precision with less wear of parts. In this patent, which he secured in 1801, he also proposed sundry improvements in the boilers, as well as modifications in various parts of the engine. In the year 1802, Bramah obtained a patent for a very elaborate and accurate machine for producing smooth and parallel surfaces on wood and other materials. This was erected on a large scale at Woolwich Arsenal, and proved perfectly successful. The specification of the patent includes the description of a mode of turning spherical surfaces either convex or concave, by a tool moveable on an axis perpendicular to that of the lathe, and of cutting out concentric shells, by fixing in a similar manner a curved tool, nearly of the same form as that employed by common turners for making bowls. Bramah also invented machinery for making paper in large sheets, and for printing by means of a roller, composed of a number of circular plates, each turning on the same axis, and bearing twenty-six letters capable of being shifted at pleasure, so as to express any single line by a proper combination of