[[Mechanicks Plate I. ― Sutton Nicholls sculp:]]
Figure. 1. This belongs to _Galilæo's_ famous Demonstration of the Velocities and Times of Bodies descending by an uniform Force, such is that of Gravity here below: And shews that they will ever fall in equal Times, 1, 2, 3, 4, _&c._ according to the odd Numbers, 1, 3, 5, 7, _&c._ or the Trapezia B C D E, D E F G, F G H I, _&c._ and by consequence, that their Velocity will increase uniformly in Proportion to the Lines B C, D E, F G, H I, _&c._ or to the Times of Descent. And that the entire Lines of their Descent will be as the Triangles A B C, A D E, A F G, A H I, _&c._ or as the Squares of those Times, 1, 4, 9, 16, _&c._
_Fig. 2._ This is a strong Balance for an Experiment to prove the former Proposition, by shewing that any Bullet or Ball, when it falls from four Times the Height, has twice, from nine Times the Height has thrice its former Velocity or Force; and will accordingly raise a double or triple Weight in the opposite Scale, to the same Height, and no more; and so for ever.
_Fig. 3._ This shews how Bodies upon an inclin'd Plane will _slide_, if the Perpendicular through the Center of their Gravity falls _within_; and will _rowl_, if that Perpendicular fall _without_ their common Section.
_Fig. 4._ This shews that an oblique Body will stand, if the Perpendicular through its Center of Gravity cut the Base; and that it will fall, if it cut not the Base: As accordingly we stand when the Perpendicular through the Center of Gravity of our Bodies falls within the Base of our Feet; and we are ready to tumble when it falls without the same.
_Fig. 5._ This is a Conick Rhombus, or two right Cones, with a common Base, rowling upwards to Appearance, or from E towards F and G: Which Points are set higher by Screws than the Point E. But so that the Declivity from C towards A and B is greater than the Aclivity from E towards F and G. Whence it is plain, that the Axis and Center of Gravity do really descend all the Way.
_Fig. 6._ Is a Balance, in an horizontal Posture, with weights at Distances from the Center reciprocally proportional to themselves; and thereby _in Æquilibrio_.
_Fig. 7. and 8._ Are two other Balances in an horizontal Posture, with several Weights on each Side, so adjusted, that the Sum of the Motion on one Side, made by multiplying each Weight by its Velocity, or Distance from the Center, and so added together, is equal to that on the other: And so all still _in Æquilibrio_.