The Explication Of the Eleventh Table

This contains the Explication of the Catapulta, which was a Machine of War used by the Ancients to dart Javelins of an extraordinary bigness. A are the two Beams one against the other, and joyn'd, which after having been drawn, pushed the Javelin with great force when they were unbent. There is one of these Beams, which is represented as being joyned to the Capital of the Machine by an Iron Pin, the other ready to be joyned when the Master of the Machine sounds the Cord with his right Hand, shall have it heightned or let down, the end marked C, as much as is necessary, to give it an equal Bent to the other. This is done by the help of an excentrical piece, which is traversed by a Cylinder, which the Master turns with a Laver, which he holds in his left Hand. D, E E is the Capital of the Catapulta. EE are the holes through which the Rope passeth to draw the Beams. F is the end of one of the Beams represented in great. G is one of the Pins which travers'd a round Eye, by the help of which the Beam is joyned to the Capital. H is the Cylinder which traverses the excentrical piece I. This Plate relates to pag. 155.