No. LVI.
To provide and make, that all the weights of the descending side of a wheel shall be perpetually farther from the centre than those of the mounting side, and yet equal in number and heft of the one side as the other. A most incredible thing, if not seen, but tried before the late king of happy and glorious memory, in the Tower, by my directions; two extraordinary ambassadors accompanying his Majesty, and the Duke of Richmond, and Duke Hamilton, with most of the court attending him. The wheel was fourteen feet over, and forty weights of fifty pounds a-piece. Sir William Belford, then Lieutenant of the Tower, can testify it, with several others. They all saw, that no sooner these great weights passed the diameter line of the upper side, but they hung a foot farther from the centre; nor no sooner passed the diameter line of the lower side, but they hung a foot nearer. Be pleased to judge the consequence.
NOTE.
The celebrated problem of a self-impelling power, though denied by Huygens and de la Hire, who have attempted to demonstrate its fallacy, has yet been supported by some of the most celebrated among the ancient as well as modern philosophers. Innumerable have been the machines to which the idea of the perpetual motion has given birth; but the most celebrated among the moderns is the Orffyrean wheel. This machine, according to the description given of it by M. Grævesande, in his Œuvres Philosophiques, consisted of a large circular wheel or drum, twelve feet in diameter, and fourteen inches in depth. It was composed of a number of thin deals, the spaces between which were covered with wax cloth, in order to conceal the interior parts of it. On giving the wheel, which rested on the two extremities of an iron axis, a slight impulse in either direction, its motion was gradually accelerated; so that after two or three revolutions it is said to have acquired so great a velocity as to make twenty-five or more turns in a minute: and it appears to have preserved this rapid motion for the space of two months, during which time the Landgrave of Hesse, in whose chamber it was placed to prevent a possibility of collusion, kept his own seal on the outer door. At the end of that time it was stopped to prevent the wear of the materials. Grævesande, who had been an eye-witness to the performance of this machine, examined all the external parts of it, and was convinced that there could not be any communication between it and the adjacent rooms. Orffyreus, however, having been informed of the ill-timed curiosity of the professor, and incensed at the refusal of a premium of twenty thousand pounds, which he had made a sine quâ non for disclosing the mechanism of its construction, broke the whole apparatus into atoms, and his life was soon after sacrificed to chagrin at his disappointment. The analogy between the Marquis's description and the Orffyrean wheel is sufficiently evident; and the experiment having been made in the Tower, more than fifty years prior to the attempt of the German mechanic, it is more than probable that the idea was derived from the noble author's work.