Let _a b c d_ represent a wooden cistern, or trough, half filled with water; E F G, three overshot water-wheels, supported by the upright piece; K is another cistern, or trough, filled with water up to the dotted lines; P is a syphon to convey water from the lower to the upper cistern K; R is a beam supported from the cistern; S T U are moveable cranks attached to the horizontal shafts through the center of the water-wheels--each crank has a connecting-rod to the beam R; V W are two curved spouts to convey water from one wheel to another. It may be well here to premise that each water-wheel has a pump and beam, as only one is seen in the section. Now, in order to put the machine in motion, it is only necessary to draw a portion of water from the syphon over the wheel E, which immediately revolves, consequently the pump L M draws water from the lower to the upper cistern K. Now, the water passing over the wheel E is collected by means of the curved spout V, and is conveyed upon the middle wheel F, which also gives motion to another pump, and draws in like manner. Again, the water passing over the middle wheel, is collected as before by another curved spout W; consequently, the lower wheel is put in action, accompanied with another pump. Hence it is obvious that three water-wheels and three pumps are worked by one stream of water from the syphon. What more is required to perpetuate its motion? John Linley. Wicker Sheffield, May 28, 1830. Device of Author of the "Voice of Reason" In 1831 a contributor who signed himself Author of the "Voice of Reason," furnished to the scientific journals of England an account of what he claimed was a Perpetual Motion Device invented by him. It should be said to his credit that he claimed no surplus power for his device--only that it would run itself. He, in fact, stated that his machine could not perform more than the simple operation of pumping its own water. The principle upon which he relied is sufficiently shown by the following figure, and the following excerpt from the contributed article: