The Main Screw.

Length, A to C, 3 in. C to B, 10 in. D the centre.

The Main Screw is thirteen inches long, three inches of the upper part is made hex- agonal, or six square, to admit the short head, and through which a pin is fixed to keep them together; at the lower end is a garter, on which the collar of the piston works, and at the bottom is a hole to receive the plug of the upper centre, as represented by the dotted lines: the screw has two threads, which of course commence at opposite angles; in putting it into the head, great B care is required that the threads commence the right way, otherwise the short head will not fit in its place so as to work with the coupling bar; consequently it must be taken out again, and without the greatest caution they are liable to fall into the same error: before the screw is put into the box, the collar at the top of the piston must be placed so as to screw on when the latter is put up. The Short Head.

DU

Length, from A to B,. 8 in. Width, . .4 and three quarters.

2

The Short Head is a piece of cast iron, in the centre of one end is an hexagonal hole made to fit exactly on the top of the main screw, through which

end is separated suffici- A the coupling bar to

passes a pin; the other ent to admit one end of work in it; holes are

made for a substantial steel bolt to pass through both these projections, upon which a nut is screwed on the bottom; this bolt secures one end of the coupling bar.

The

From A to B, I in. and a half. The Arbor is a round cast and a half long; one inch is a round projection, admit the bar, on which a site side: four inches from rests one end of the top hexagonal above the collar,

which is also fastened

Arbor.

B to C, 9 in. C to D, 4 in. iron pillar, fourteen inches and a half from the bottom through which is a hole to nut is screwed on the oppothe top is a collar, on which plate the arbor is made to admit the long head, on with an iron pin.

The Top Plate.

Length, from A to B, 8 in. Width, 3 in, and a half. The Top Plate has two holes in it, one to admit the upper part of the arbor,

through it; and the A

which fastens it to the

B

above the collar,to pass other is for the screw top of the staple; part

of the plate being cut away to fit exactly on the last mentioned; and by which means it appears to form a part.

The Long Head.

Length, from A to B.

9 in. and a half.

The Long Head is cast somewhat like that of the short one; only with this differtion rises a little above arbor, or cheek, to the pull is made; the latter

A

B

ence, the front projecthe top, which forms an coupling-bar, when the having to pass over the

top of the long head and arbor. The other end of the coupling bar is attached to it, as before described, in the short head.

The Coupling Bar.

Length, A to B, 15 in. and a half. Width, 1 in. and three quarters. The Coupling Bar is a flat piece of wrought iron, made round at one end, with a hole through the centre, which is connected to the long head; the other end is rounded a little with a square head through which AOK B passes a screw, and by it the power is regulated: this presses against a washer which fits in the oblong hole, and through the screw that connects the bar with the short head; there is also a projection on the side which checks against the arbor in the long head, when the pull is made.

The Bar and Handle.

Length, 21 in. Shauk, 3 in. & three quarters.

Thebar is shaped a form here reprefits into the hole the arbor, and is the end; the

Handle, 5 in. somewhat in the sented, the shank in the circle on screwed fast at handle is made

of wood, and rivetted at the extreme point.

The Piston

A to B, 17. C to D, 12 in. and a quarter. Is of cast iron, with a bowl at the upper which is placed the lower centre; on works: the inside of the

ed to receive the screw upon the garter of the the latter is completely when the Piston is put under the collar are two rest upon the ends of which the piston and A

D

E to F, 5 in. and a half. part, at the bottom of which the upper one top of this bowl is tappof the collar which rests spindle; the bottom o enclosed in the bowl up; on each side, just small knuckles, which the balance iron, and by plattin are raised up af made; the sides are bevelled off, and made to fit exactly against the bevels on the inside of cheeks; a hole is tapped at the back to receive the screw which draws the piston close to the back plate: the four holes

ter the impression is

NOTWITHSTANDING we had presses made by several individuals on the Stanhopean principle, which were considered fully adequate for every purpose, yet some persons were induced to bring forward others, in the expectation of sharing the profit arising from what was generally consider ed a lucrative employment: the first of these was invented by a German of the name of D'Eighn, which was known by the appellation of

THE SECTOR PRESS.

This press was much like the Stanhopean in formation: the principal difference consisted in its having Sectors instead of the Screw, and also in its having a large screw through the head, for the purpose of regulating the power, in place of its being at the end of the Coupling Bar, as in the Stanhope; this we consider as no improvement, because it was not so readily turned; neither where the Sectors of that advantage, for it not unfrequently happened that they would fly from the great pressure. Mr. D'Eighn afterwards disposed of his patent-right to a person of the name of Golding, who continued to manufacture them for some time. He then invented another press, and soon afterwards died, when his widow disposed of the patent to Mr. Cogger. THE field was next entered by a firm of the names of Cogger and Scott, their press was denominated

COGGER'S PRESS.

They were composed of two upright pillars of wrought iron, upon which the cast iron head was screwed: it had Sectors, and a Screw on the head for regulating the power, similar to the first patent; the Plattin is secured by two rods, which pass through the Head and Till, and are fastened to the Plattin by two small pins; and by which the Plattin and Bar are returned by the power of the two Spiral Springs which pass over the rods, and are screwed down to the Head by nuts on the top of the rods; the power is given by compound levers, after the manner of the Stanhopean: a great objection in these presses arises from the insecure manner of the Plattin, which is by no means so effectually secured as it ought to be; we have known them to shake by the power of a person's single hand; they have a great quantity of ornamental brass work, which give them a pleasing appearance to the eye, but it is not the glitter of guady tinsel that a practical printer wants.

THE next that came forward was Mr. Ruthven, a Printer, at Edinburgh, he materially differed from all his predecessors; his was stiled

THE RUTHVEN PRESS.

This press occupies less room than any of the former, being nearly square, the Table of which is stationary, and the Plattin is drawn over by the hand, being supported by two iron springs, under which are four brass bevelled wheels,