Theatrum naturae et artis

Static instruments and their powers also relate to this, and they are: the common balance, (a) of which a species is the assay balance; (b) the steelyard; (c) and the natural balance. (d) To these is added a completely new type of weighing by coils original: "spiras", (e) which is brought to greater perfection daily.

(a) Its parts are indicated, and it is shown in how many ways the goodness, faults, and deceits of the whole balance may be detected. The force of equilibrium is also demonstrated in a small machine.

(b) Its parts, common with the ordinary balance and besides those also its own, are shown, along with peculiar weights which are accustomed to be used in the examination of metals.

(c) Its structure, parts, and method of weighing are shown.

(d) Its use is mainly in hydraulics, and it is estimated not by equal mass, but by equal perpendicular.

(e) Enclosed in a cylinder, which, when a weight is attached, are either extended or compressed, and indicate a weight of 20, 30, 45 lbs., etc., on an emerging column.

When we descend to the various kinds of motion, we first investigate its causes regarding the straight motion of light and heavy bodies (a), and to these we add a few paradoxes (b).