We would here notice the probable cause of the Marquis's indefatigable study of, and attention to, practical mechanics. As in the time of Charles II., so also during the reign of his father, there is reason to believe that some distinguished public officer was appointed to superintend Government works connected with the army and navy, and that they were situated at Vauxhall. It was probably a department similar to that held in 1661, by Sir Samuel Morland, designated Master of Mechanics. Otherwise how are we to account for the Marquis of Worcester's devoting his time, his energies, and his very fortune to inventions affecting mechanical appliances generally, and particularly to those connected with naval and military affairs, and hydraulic engines? One of his inventions (No. 56) he exhibited to Charles I. at the Tower, and of another (No. 64) being an improvement in fire-arms, he observes it was "tried and approved before the King (Charles I.), and an hundred Lords and Commons." Then his great invention, the "Water-commanding Engine," was set up at Vauxhall in 1663, where it was certainly at work in 1667, or probably three years later. All these circumstances wear the aspect of royal patronage, of public employment, and of the possession of influence suitable to the holder of a dignified position. This view of the high and honourable public official position held by the Marquis is also borne out by the petition of William Lambert, about 1664, to be found in the State Paper Office. It was addressed to Charles II. and sets forth:--"That your petitioner was founder to his late Majesty of blessed memory, in Vauxhall, under the Marquis of Worcester, for gun and water-work, or any other thing founded in brass." Nothing surely can be more certain than that the Marquis's was a public situation, and his "Century" affords ample evidence of his aptitude in _that_ respect for the post which he filled; nor can we better account for his numerous improvements in fire-arms, cannon, sailing vessels, fortifications, and embankments.