To raise weight as[7] well and as forcibly with the drawing back of the Lever, as with the thrusting it[8] forwards; and by that means to lose no time in motion or strength. This I saw in the _Arcenal_ at _Venice_.[9] Footnotes [7] so--for as. [8] of it. [9] at Venice in the arsenal. [_A to and fro Lever._] William Bourne offers the following as his 112th Device, “touching the making of engines to thrust from or pull to you with great force or strength.” He says, “And furthermore, you may make an engine to thrust from you or to pull unto you, to lift vp or to presse downe with great force, eyther to goe with wheeles as before is declared, or else to goe with skrewes or to goe with both, as to thrust open huge and strong gates, or else you taking good hold, to pull them open vnto you wards, and will make but little noyse in the doyng thereof, but you must be sure to set the engine fast, if to thrust from, to be strongly and well backed, and to pull to them it must be strongly bolstered before, sufficient to be of force to scrue the turne.” [Illustration: A to and fro Lever] The Venetian arrangement may be described, as shown in the annexed engraving, where A, B, C, is a frame, the two upright sides of which D E, are provided with a series of clicks, appearing in the drawing like the serrated edge of a saw, and each is so placed secured by a pin on which it moves, as always to incline to fall outwards. F, F, is a long lever, having a stout short cross bar in the centre, and is represented on the point of taking up on a click at _a_, while it leaves one on the opposite _b_, such being the _to_ and _fro_ motion required, thereby losing “no time in motion or strength.” 27. A way to remove to and fro huge weights with a most inconsiderable strength from place to place. For example, Ten Tunne with ten pounds, and less; the said ten pounds not to fall lower then it makes the ten Tunne to advance or retreat upon a Level. [Illustration: A most easy level Draught] [_A most easie level Draught._] The weight is in this case to be moved “with a most inconsiderable strength.” Ten pounds, or less, are to be capable of moving 22,400 pounds. And the precise conditions are--“the said ten pounds not to _fall lower_ than it makes the ten ton _to advance_.” The annexed engraving shows, as in No. 25, two cylinders B, C, with their steam-pipe and valve at A, having above a platform G, on which is a loaded truck F, attached by a cord _a_, at one end passing over a pulley, and the drum wheel D, to the piston B; and a second cord at the other end passing over a pulley at _a'_, attached in like manner to the other piston C. Steam having been admitted to B, on its condensation the piston descending draws along with it the weighted truck F, while the piston C, ascends, drawing in air at E. We thus attain the strict letter of the conditions set down, the _fall_ and the _advance_ being equal. 28.