Machine for drawing iron into cannon barrels

Drawing iron staves to form the cannon's bore

The iron rod is first hammered near to shape, then drawn to impress the course of the ball for the bore of the piece; the sides are finished true, and the fourth side, forming the barrel's surface, is made with the wheel a.

The helical wheel (elica) and its definition

The wheel is surrounded by a composite helix. A helix is a pyramid bent into circular curvature; if two of its four sides are parallel it is a simple helix, if they converge to a point a composite one. The word derives from 'elis', the tendril of the vine.

Four worm-screw wheels graded by power

Make the members of the instrument equal to or greater than the power of their motors. Four driving wheels of endless screws are each marked with the degrees of their power, held true by the thirteenth proposition of the twenty-second book of his Mechanical Elements; wheels may be added or enlarged to raise the force.

Force multiplied twelvefold at each gear

The gear train is tabulated from the prime mover n: 1000, 12000, 144000, 1728000, 20,736,000. Each stage multiplies by 12, the lever being twelvefold to its counter-lever.

As many dies as staves; the iron of the Genoa mole

At m and n stand the ends of the first and second drawings, the latter finishing the staves that compose the barrel. Iron drawn from a ruin of part of the mole of Genoa took less power than this; one die is made per stave, so that their uniform wear makes all staves equal.

Figura centrale colle lettere:

A sinistra dall'alto in basso:

Figura di ruota a elica:

In basso. Figura di ingranaggi con - dal basso in alto - una lettera e i numeri:

A sinistra:

A destra. Figure colle lettere:

Nella figura in basso:

Central figure with the letters:

On the left, from top to bottom:

Figure of the helical wheel:

Below. Figure of gears with, from bottom to top, a letter and the numbers:

On the left:

On the right. Figures with the letters:

In the figure below: