DECLARATION

Declaration of the 10th figure.

The base of this lathe is like a workman’s table. On its surface, at the northern side, rests the stone to be polished for the smith. Opposite is a balance, which the smith pulls toward himself with his left hand by means of a cord tied to it, measured from the head of that balance which turns toward the north, 1 measure 6 palms. With his right hand, the same smith leads the polishing or cutting iron.

Two arcs cling to the head of the balance, at the end of which are rods placed crosswise one upon the other, whose assembly I like to call an "Attelabus" [locust] from its resemblance to the feet of a locust. This attelabus, when the head of the balance recedes, pulls back the polishing iron, and when it approaches, draws it forward.

PROP. XI.

A species of new counterweight which, moved by the hand of one or another like a struck bell, has so much power to drive two, and those immense, bellows in mines, that they can equal those which are promoted either by the force of waters or by horses driven in a circle.

Declaration of the 11th figure.

These are easy. To the east are the air vents [ciniflones], and the counterweight itself, suspended from a beam, the height of which is 2 measures 3 palms. Nearby are the bellows, then the furnace, which is almost similar to common ones, except for the counterweight.

PROP. XII.

A machine which ought to follow the preceding one, both in novelty and excellence, for applying such a huge hammer upon an anvil, by the labor of two men, that you could accomplish nothing more with either horses or waters.

Declaration of the 12th figure.

The whole account of this vehement motion depends upon a larger wheel, which, when moved, has the greatest force; but that we may better perceive the matter, all things must be declared specifically. Toward the east, measured from the southern line to the northern, 1 measure 2 palms, is the anvil. And next, measured from the eastern line to the western 6 palms, and from the southern to the northern 2 measures 6 palms, is the hammer, whose handle turns toward the wheels that are in the north, of which the middle one is the largest, and two side ones are equal to each other and smaller than the middle one, all of which cling to one and the same axle. Now, by this axle, when the handle is pushed this way and that by the workers, the wheels are moved, so that the little pegs fixed in the axle, striking the arms of the hammer’s handle, lift the hammer so that, once the pegs are released, it strikes the anvil, which is not difficult to perceive from the figure.

PROP. XIII.

A new machine for cutting trees, through which as much work is performed by the agitation of two workers as eight could accomplish by the common method, provided it is set up in a depressed place and in which trees can be extracted on level ground.

Declaration of the 13th figure.

The structure of this machine turns from east to west, resting on four twin (so to speak) timbers, of which two that are in the third position, being larger from the east, are 3 measures 8 palms, between which are two equal arms which are moved by two hinges in which they are transfixed while moving. These hinges are distant from the base 1 measure 12 palms. From the eastern part of the arms hang saws [runcinæ], the part of which in which the arms are transfixed has free motion around them; then the saws are constrained by a square hole at their last northern part, distant 1 measure 2 palms. The rest pertains to the motion, which must be diligently considered. In the west are twin wheels, of which one appears, to which the other is similar, differing. The reason for that axle is the cause of the saw’s motion up and down, for it is bent in the middle like a spit handle, and in the parallel part of the axle are two iron arms which reach to the extreme western part of the arms carrying the saws, so that by these newest arms the others are pushed and pulled when the wheels are moved by the hands of men, one straining on this side, the other on that. Again, there presents itself a wheel from whose hub arise twelve spokes which are pushed by this peg appearing on that movable wheel, so that by the cord wound on its axle it gradually draws the tree to be cut—at whose eastern end the last part of the cord adheres—toward the saws. Which was to be said.

PROP. XIIII.

Another new machine, which, placed in the same location as the preceding, performs with the labor of one person—when necessity urges—the same thing as the superior one does with two, as its delineation and mathematical ratio show.