Theater of Machines, Volume 4

More on the utility of Mechanica or Geometria Practica see Johannes Faulhaber, ch. 381.

trispastos three-pulley system and polyspastos multi-pulley system increases it infinitely in the right order and proportion: in the way that it could be made quite evident through exempla examples. However, we want to skip here all subtleties, such as the principia principles of this art, along with the geometrical arguments with which such might be demonstrated, and mention only very briefly what instrumenta instruments or tools are especially used therein, and what excellent work-masters and artifices craftsmen this art has had in former times. Concerning now the first, if we take only the aforementioned Tractoria or pulling-art for ourselves, we find that for Mechanica, in that it lifts or pulls great loads up into the heights, the following instrumenta are primarily used.

The most prominent tools of Mechanica.

1. The screw-winch or disks along with the small wheel on the axle, through which the tow-rope goes, trochlea. 2. The tread-wheel, which one treads or in which one walks to pull something up, is otherwise called the crane, tympanum.

Tympanum. Ergata. Succula.

3. The winch-beam from Vitruvius, called ergata. 4. Succula, the traction-shaft or pulling-winch, which is driven around with levers or winch-bars. And 5th, the lifting-bar, lever, or spar, with which one heaves something; it is pointed at one side, called vectis or mochlium; that however which is pushed under the load is called hypomochlium.

For what the lifting-bars are useful, and who uses them: builders.

There would be much to report about these 5 tools; I only want to mention something of the last, namely the lifting-bars or the lever, which has such power that, where the under-lever or hypomochlium is placed under the load, a single man with the lever or spar can heave or lift such a weight as many men with all their force could not otherwise move. However, this lever is also useful for very many other things, so that it is indeed to be wondered at. Builders and carpenters use it at times, as mentioned, to lift the heavy load: at times they use it in a winch-bar or winch-handle. Gardeners use