Theatrum naturae et artis

perpendicular: and in the pushing or driving of an inclined plane by the proportion of the base to the perpendicular.

(e) It is a double inclined plane, and indeed that which is pushed, hence the same proportion is to be observed.

(f) It is a perpetual inclined plane, where we observe the circumference of one helix and the distance between the helices; hence, as the circumference of the helix relates to the distance between the helices, so also the moving force is increased.

(g) From the so-called bladder; which, if inflated, can lift a weight of thirty pounds and more, by its contraction.

The application of these is shown in various composite machines by resolving them into these simple ones, for example: in a step-counter, which records our steps without us noticing; in a carriage that can be steered by one man without horses, and another by two; in a plow, both smaller and larger, by which we have been taught by experience itself that not only is there a saving in labor, but sowing can be done with a smaller quantity; in a wooden machine, equipped with two wheels and one screw, by which a tender boy can lift one hundred pounds with little effort; in another machine, by which a great mass, e.g., the statue of the King of France, was moved on a plain by a few men, which could not be pulled by many horses; in various other small machines, a mouse, a stag, a rustic driver, maidens running here and there; in a compass, whose opening is made by a rectilinear screw; in an Italian candelabrum, etc.