With respect to his question, whether a circulation of water would be kept up by the arrangement, I answer, no; as the velocities will be in the inverse ratios to the forces, and the descending column of 120 inches must expend itself forty times to raise the ascending one to the height of twelve inches, as proposed:-- 10 ft. or 120 in. × 40 = 4,800, lifting force or power. 400 in. × 12 = 4,800, opposing force, resistance, or weight. Here is an equilibrium, and nothing gained to overcome friction or the weight of the atmosphere on the piston of the pump. Were it possible to annihilate both friction and atmospheric weight, even then, unless the power exceed the weight, the power would not be a moving one. A Perpetual Pump, by an Unknown Inventor In Volume I of "Mechanics' Magazine," 1823, appears an account by a correspondent of a Perpetual Motion device which is illustrated by the figure, and the quotations following: _a b c d_ is the section of the reservoir, &c., showing the wheel, the pump, &c. A B is an overshot water-wheel; C D the working beam; E the pump; F a pipe from the top of the pump, through which the water was to fall upon the wheel; C G an arm, communicating, by means of a crank attached to an horizontal shaft through the centre of the wheel, motion to the lever or working beam, and so raising water from the reservoir by means of the pump; H I the water. It was supposed that the water which had fallen upon the wheel into the reservoir would be raised by means of the pump, fall through the horizontal pipe, and so produce a continued rotary motion. [Illustration] The persistence of Perpetual Motion workers is amusingly illustrated by the inventions of William Willcocks Sleigh and Burrowes Willcocks Arthur Sleigh. Their devices were so extremely complicated and not susceptible of being understood, and hence are mentioned rather than shown in this work. In 1845, William Willcocks Sleigh, a doctor of medicine and surgery, of Chiswick, Middlesex, England, applied for and obtained British Patent on what he called "A Hydro-mechanic apparatus for producing motive power." He took out other patents on hydro-mechanical devices in 1853, 1856, and 1860. Then in 1864, his son, Burrowes Willcocks Arthur Sleigh took out two patents on similar devices, and then in 1866, still another patent. The specifications for each of the above mentioned patents are lengthy and detailed. The inventors evidently had the greatest confidence in their efforts, though surely they never put them to actual test. They seemed to have been mechanically stupid, and incapable of correct mechanical thinking, but their efforts were so tireless and so earnest that we submit that the Sleigh family had done its full, fair share in the efforts to accomplish Self-Motive power.