Theatre of Instruments and Machines

Those who understand the use of the architects' pulleys or "Rechami" can understand the proposition from the figure without a declaration: but let us state the parts of this mechanism.

To the north is a frame carrying a winch by which everything is moved, for that winch is led from the west into the east, in the western part of which is a wheel with a handle; for, as has been said often, the motion of the larger wheel can do much in these things. Again, there is a beam parallel to the axis, at each extremity of which is a pulley. Then, toward the south, is seen a pipe in the apex of which is present a block-and-tackle of two pulleys, around which, as around the upper ones, the cord is rolled so that the eastern part of the cord, wrapped around the lower eastern pulley, is referred to the upper eastern pulley, then to the upper western one, and again to the lower western one, so that at last both meet at the winch in the circumvolution. Experience will teach the truth of this: for when the winch is moved, the block-and-tackle is lifted by two parts, which is the entire subtlety.

A machine invented for the same thing, by which water is led upward from any well whatsoever without intermission, even without tubes and valves, and that by the alternate and balanced motion of a balance-beam.

I will explain those things which appear here, whose utility is not small, since much water can be drawn either all day long, provided the labor of two men is present. Therefore, one sees in the meridian line at the bottom of the well a rotatable drum around which is an endless chain that is wound around another similar to it which is to the north above the well; on that chain are many freely hanging buckets, which can be brought and led back without end, provided it is understood how it is keyed. This, however, is as follows: there are three axes in the frame, the middle of which is distant from the meridian line 2 measures and 22 palm-widths, in which is the aforementioned drum toward the east, and another also toward the west, which is keyed. This axis always moves uniformly, but the other two only with half-motion, in which are two wheels to the west, in whose middle part are pegs in place of teeth. In the eastern part are two rollers partially toothed, in one of which is fixed a balance-beam, the motion of which is led and led back. That balance-beam, when impelled, moves everything. And only the two outer axes perform half-motion: but by the work of the toothed wheels entering into the drum, the middle axis is always moved, one roller into one part, the other into the other, being exerted; thence hangs the excellence of this machine, which the diligent explorer will not despise.

A recent type of mechanism, by which it is permitted to one or more, safely, both to descend and to ascend into a mine, however deep it may be, and thence to extract the dug-up metallic ores.

The subtlety of this machine is in the screw which we have called infinite. This is in the eastern part of the machine, which is suspended by a chain, and is distant from the northern line 1 measure and 20 palm-widths, and from the western line 1 measure and 2 palm-widths. The reason is patent from what has already been said, and the rest is easy: for when the screw is turned so that it may be carried upward, it never revolves, and vice versa.

A new instrument based on a balance-beam, by which flowing water is lifted to a certain height and inundates land to be irrigated, while the wheel remains hidden within the water so that it does not crack from the heat.

First, here is to be noted the balance-beam, in the extremities of which are two buckets, of which one is in the water toward the angle of the west and south, the other, elevated, verges toward the angle of the east and north; the middle of the balance-beam is distant from the meridian line 2 measures and 8 palm-widths, and from the western line 1 measure and 4 palm-widths; but [it is] constrained between...