A double Water-scrue, the innermost to mount the water, and the outermost for it to descend more in number of threds, and consequently in quantity of water, though much shorter then the innermost scrue, by which the water ascendeth, a most extraordinary help for the turning of the scrue to make the water rise. [_A double Water-scrue._] The arrangement of this simple invention is so clearly and amply set forth, that it is a wonder it could ever have been misunderstood; yet it so baffled Mr. Partington, that he classes it among “extraordinary sleight of hand discoveries.” M. Pattu, a French engineer, in 1815, published his account of a double water-screw of this description which he had invented, capable of being applied in three different ways, the construction, however, in all being the same. In one arrangement, the enlarged end of the screw is about one-eighth part that of the entire length of the internal or lesser screw, and it surrounds the “innermost” screw, the spirals winding in a reversed direction. The top of the shorter or “outermost” screw may be on a level with a stream of water “for it to descend” therein, to promote “the turning of the screw” (of greater length and smaller diameter) “to make the water rise,” from a lower stream. In a second application, the long screw may be used to propel the short one, to raise water a moderate height. Or, thirdly, the enlargement may form the upper end, and be used to propel from above, instead of from below, as at first described. 56. To provide and make that all the Weights of the descending side of a Wheel shall be perpetually further from the Centre, then those of the mounting side, and yet equal in number and heft to[7] the one side as the other. A most incredible thing, if not seen, but tried before the late king (of[8] blessed memory) in the _Tower_, by my directions, two Extraordinary Embassadors accompanying His Majesty, and the Duke of _Richmond_ and Duke[9] _Hamilton_, with[1] most[2] of the Court, attending Him. The Wheel was 14. Foot[3] over, and 40. Weights of 50. pounds apiece. Sir _William Balfore_,[4][K] then Lieutenant of the _Tower_,[5] can justifie[6] it, with several others. They all saw, that no sooner these great Weights passed the Diameter-line of the lower[7] side, but they hung a foot further from the Centre, nor no sooner passed the Diameter-line of the upper[8] side, but they hung a foot nearer. Be pleased to judge the consequence. Footnotes [7] of--for to. MS. and P. [8] of happy and glorious. MS. and P. [9] of, omitted. [1] and--for with. [2] most part. [3] feet. P. [4] Belford. MS. and P. [5] and yet living can. [6] testify--for justify. P. [7] upper--for lower. MS. and P. [8] lower--for upper. MS. and P.