levers i, and m, have straps o, o, connecting them by joints to a right-angled lever p, which carries a heavy weight, made adjustable upon the tail of the lever, for the purpose of counter-balancing the additional weight of the form when placed upon the table.

Pendant from the joint, at the bottom of the stem h, is an arm q, forming the upper piece of the toggle-joint, which arm is taken hold of by the bolt or tappet-pin, on the main shaft e, as it revolves, and thereby causes the stem h, with the table ƒ, and form of types, to be raised. At the same time the other tappet-pin, on the main shaft, acts in a similar way on the end of the other toggle-piece r, which causes the cross-head 1, to descend and bring down the vertical sliding rods k, k, and the platten g, toward the table; by which combined action the pressure is given. When, by the rotation of the main axle, the tappet-pins have escaped from the toggle-pieces q, r, they are brought back to the quiescent positions shewn in fig. 1, by weighted tail-pieces, which respectively fall against stops, and thereby retain the ends of the toggle-pieces, in such positions as will allow the tappet-pins to take hold of them again when brought round by the rotation of the main shaft.

The movements of the frisket are produced by a tumbling shafts, (seen in fig. 2,) which shaft is connected by an universal joint to the shaft of the pinion c, before mentioned, and is thereby made to revolve. The reverse end of the tumbling shaft has a pinion t, which takes into the teeth or pins of a mangle-wheel u, mounted on a transverse shaft, supported by bearings on the side-frames. Upon the outer end of the shaft of the mangle-wheel is affixed a toothed-wheel v, taking into a pinion on the end of a transverse shaft w, which carries the two chain-wheels x, x, whereby the frisket is conducted to and fro. There are four of these chain-wheels x, x, x, x, two of them being

shewn in fig. 1; and over these wheels two endless chains y, y, are extended, and by the ordinary operation of a tumbling shaft, acting in a mangle-wheel, these chains are made to travel to and fro, with a reciprocating action.

Studs z, z, set into the sides of the chains at certain intervals, pass into upright slotted guides A, A, standing up from the frisket-frame B. Hence it will be perceived, that as the chain goes round in one direction, the studs z, z, having passed into the slotted guides A, A, will draw along the frisket-frame B, which slides in grooves upon the upper edges of the side-frame of the machine; and when the frisket-frame has proceeded so far as to allow the studs to pass up out of the slotted guides, the frisket-frame will then remain quiescent, which takes place at the time that the impression is being given. This interval of rest allows time for laying on a fresh sheet, and when the contrary rotary movement of the mangle-wheel (by which the chain is conducted in the reverse direction) takes place, the frisket will, in like manner, be conducted back again, and the fresh sheet receive its impression.

The inking-rollers c, c, c, turn on axles, mounted in eyes at the outer parts of certain links of the endless chains; and as they are conducted to and fro by the chains, through the agency of the mangle-wheel, as before described, they receive their ink from a distributing surface D, which is fed from a ductor E, at the top of the frame, by the distributing rollers F, F, F, which travel from end to end of the machine, upon horizontal rails G, G; and as the inking-rollers, in the lower part of this circuit, pass over the form, they communicate their ink to the surface of the types.

A side elevation of a cylindrical printing press is shewn at fig. 3, the mechanism of which is mounted in a frame a, a, a. A rigger b, is fixed upon the end of a short shaft e, carrying a pinion d, which takes into the toothed-wheel

e, on the shaft of a cam-wheel ƒ. A tumbling shaft is connected, by a universal joint, to the shaft c, and at the other end of this tumbling shaft there is a pinion, taking into a horizontal mangle-rack g, which rack forms the bottom rail of the frame h, h, carrying the table and form of types A, B. Hence, as the pinion of the tumbling shaft works in the upper and lower sides of the rack g, it drives the table to and fro. On the side of the table there is another horizontal rack, taking into a toothed-wheel on the shaft of the pressing cylinder k, by means of which, as the table passes to and fro, a reciprocating rotary motion is given to the pressing cylinder.

The sheet to be printed is fed in and taken hold of by gripers i, and by the horizontal progress of the table, the sheet is brought round such a distance as exactly to meet the first line of the form A, of types, placed upon the table.

The axle of the pressing cylinder is mounted in plummer blocks, supported by vertical rods l, l, which slide up and down in sockets, affixed to the side-frames; the lower ends. of these rods being acted upon by springs m, m, which force them upwards. An infinite lever or knee-joint, formed by two pieces n, n, bears against studs set in the sideframes, and is supported below by a brace, affixed to the vertical rods l, l. An arm p, extending from the axle of the lower piece n, has an anti-friction roller, which works against the periphery of the cam-wheel ƒ; and hence, as the larger radius of this cam-wheel comes into operation upon the end of the arm p, it will be depressed, and the two portions of the infinite lever or knee-joint n, n, be brought into a straight line, thereby drawing down the rods 1, 1, and the pressing roller k, and producing the impression. The table, by these means, will be carried to the opposite end of the frame to that in which it is seen in fig. 3, and the tumbling shaft, now acting upon the other

side of the mangle-rack, will cause the table to return, and the pressing cylinder to revolve in the reverse direction.

The first-described rotary motion of the pressing cylinder will have brought the edge of the printed sheet of paper up to the tape rollers q, q, which are turned by a band from the motive shaft c; and these rollers and their endless tapes, turning in opposite directions, will take the sheet round the roller r, and deliver it between the rollers s, s, again on to the periphery of the pressing cylinder, ready to receive the impression on its reverse side from the form B, as the table returns, the depression of the cylinder being effected by the same means as before described.-The method of inking the types is the same in this as in all other cylinder machines.-[Inrolled at the Petty Bag Office, December, 1841.]

Specification drawn by Messrs. Newton and Son.

TO THOMAS JOHN DAVIS, ESQ., of 5, Bloomsbury-place, Bloomsbury-square, for certain improvements in the form and combination of blocks of such materials as are now used, or hereafter may be used, in building, or for paving public and private roads and court-yards, or public and private causeways and sub-ways, or any other purposes to which the said form and combination of blocks may be applied.-[Sealed 8th August, 1840.]

THIS invention consists of improvements in the form and in the modes of combining blocks for paving and other purposes.

The blocks are composed of wood, iron, stone, or any other materials now in use for paving or building, and are made of the forms shewn in Plate XI,, at figs. 1, 2, and 3.

Fig. 1, is a single rectangular prism; fig. 2, is a double rectangular prism, formed by placing the prism. a, fig. 1, 2 G

VOL. XX.

upon and across the middle of the upper surface of the prism b, which differs in shape and size from the prism a; and fig. 3, is a treble rectangular prism, composed by placing the double rectangular prism, fig. 2, upon the single rectangular prism, fig. 1.

The blocks are combined in various ways, (not very clearly described in the specification,) for the purpose of paving roads, and are kept in a vertical position, the combination being strengthened by passing iron or wooden rods through them. They may be so placed as mutually to support each other, without having any openings or spaces in the surface of the road or way; or they may be so placed, that spaces between the blocks are left for stone or other substances, to be filled in, which will prevent horses or other animals from slipping. The blocks are also used in the construction of the arches of railway bridges, &c., being bound together by iron or wooden rods.

The patentee claims, Firstly,-The shape of the compound blocks or prisms, which he calls stereo-prisms.

Secondly, The mode of combining the same, and the mode of employing, in combination, for building, paving, or any other purposes, any blocks, materials, or substances, of such form or shape.

Thirdly, The application and introduction of iron or wooden rods, for the purpose of keeping the compound prisms, or a combination thereof, in a vertical position, and thereby strengthening the same.

Fourthly,-The application and introduction of stone or other materials, into the spaces of the peculiar mode of combination of compound prisms, when such spaces occur therein, whereby the sliding or slipping of animals, on the surface of any such combination, will be very much or altogether prevented.—[Inrolled in the Inrolment Office, February, 1841.]