suitably grooved for securing a firm foot-hold for horses and other animals.

Fig. 11, is a plan of an apparatus for forming mortices in the sides of the blocks, for the reception of keys, as described in the second improvement.

The right-hand side of the apparatus is used for those blocks which are to be morticed on two sides only, as shewn in figs. 2, and 3; it consists of a frame a, which can be adjusted to the size of the blocks, by means of the screws b, and slots c, and of a cutter d, composed of a toothed disc, enclosed between two sharp-edged side plates, as represented in the edge-view of one of the cutters at fig. 12. The block of wood is introduced between the sides of the frame a, and a mortice is made in its side by the revolution of the cutter; it is then turned, and a corresponding mortice is formed in the opposite side.

When the block is to have a mortice in each of its four sides, the left-hand side of the apparatus is used, which is furnished with two circular cutters, and a mortice is formed in two sides of the block at the same time.

The fifth improvement consists in apparatus for cleaning and repairing the grooves in the upper surface of wooden pavements.

The first instrument is a rake, for cleaning the dirt out of the grooves, the teeth of which can be set at any required distance apart, and are of the same shape as the grooves. The other instrument or apparatus is employed for cleaning, and likewise for repairing or renewing the grooves; a side view of it is shewn at fig. 13. e, is a frame, mounted on four bevil-edged wheels f, which travel in the grooves of the pavement; g, is a cranked shaft, working in bearings at the upper part of the frame, and upon this shaft a fly-wheel h, is mounted. i, is a horizontal shaft, furnished with six or more bevil-edged cutters j, according to the width of the apparatus, set at the same distance apart as the grooves in the surfaces of the blocks; it is supported by levers k, one at each side of the machine, which turn upon the axle of the fore-wheels, as a fulcrum, and the shaft i, is raised or lowered by turning a screw 7, that acts upon the outer

end of each lever. Motion is communicated from the fly-wheel to the cutter-shaft by the endless band m, which passes under the binding pulley n, and round the pulley o, and thence back to the fly-wheel. The machine is pushed along, or across the road, by a workman, whilst another man stands upon the platform p, and, turning the shaft g, causes the cutters to revolve, and throw the dirt from the grooves into the box q; but the way in which this is effected, is not clearly shewn in the drawing attached to the specification.

When the grooves are required to be deepened, the cutter-shaft is lowered by turning the screws .

The patentee claims, firstly, the block represented in fig. 1, and the application thereof, as also shewn in that figure; secondly, the manner of connecting wooden blocks for pavements, by means of keys, tongues, or tenons, inserted into indents, chases, or mortices, as herein described and shewn; thirdly,-the system of uniform grooving of the upper surfaces of wooden pavements, and its application, in the manner, and for the purposes herein described; fourthly, —the arrangement of machinery for cutting and preparing wooden blocks for pavements, described and shewn in figs. 10, 11, and 12; and fifthly, the machinery for clearing and preparing the grooves in the upper surfaces of wooden pavements, as described and shewn in fig. 13.-[Inrolled in the Inrolment Office, December, 1842.]

TO JOHN PERRING, of Cecil House, 85, Strand, in the city of Westminster, hat manufacturer, for improvements in wood paving,-partly communicated by a foreigner residing abroad.-[Sealed 7th July, 1842.]

THE first part of these improvements consists in forming and combining together blocks of wood, in the manner represented at fig. 1, in Plate IV.

The blocks are cut from squared timber, having the core as near the centre as possible; and, supposing the timber to be six inches square, the cuts are made at distances of six inches apart, measured perpendicularly between the planes of the sections, so that the vertical depth of each

block will be equal to the distance from a, to b. They are cut across the grain, at an angle of 45o with their upper surfaces, or any angle between 400 and 45°. By this method of forming the blocks, the pressure on the outer and weaker fibres will be supported, in a vertical line, by the central and stronger fibres of the wood.

The blocks are pinned together, at their sloped and vertical sides, by pegs or pins c, d, placed at the points of intersection of lines drawn diagonally across those sides; and they are laid down in masses, consisting of from sixteen to twenty-four blocks; the outer sides of those masses that are situated at the edge of the road being cut off in the line e, f, so that they may abut firmly against the gutterblocks. The courses of blocks incline, alternately, in opposite directions, and thus break joint in the direction of the line of traffic.

The second improvement consists in paving roads with blocks, cut across the grain at an angle of from 75o to 80°, as shewn in fig. 2, and pegged together, at their vertical sides only, by two pegs instead of one, which are situated upon a central line, parallel to the upper and lower surfaces of the blocks. In carrying out this improvement, the wood, of which the blocks are made, is older and of a closer grain than that used in the first improvement, and the fibres are, consequently, of a more uniform strength.

The third improvement consists in connecting blocks together in the manner shewn in figs. 3, and 4.

In these modifications, the blocks all incline in the same direction, but are caused to break joint. At fig. 3, they are connected together, at their vertical sides only, by pegs c, disposed upon a central line, parallel to the upper and lower surfaces of the blocks. The blocks, shewn at fig. 4, are connected at the centre of their inclined sides, by the insertion of pegs.

The fourth improvement consists in separating the courses of blocks by slips of wood, for the purpose of affording a secure foot-hold for horses and other animals.

Fig. 5, is a side view, and fig. 6, an end view, shewing the method of attaching the slips to the blocks. g, are the

slips, which are fastened to the sides of the blocks, by pegs c, and, as the slips are of considerable length, they serve to connect together a number of blocks in the same course, and thereby render unnecessary the pins d, used in fig. 1. The surface of the pavement presents an appearance similar to that produced by grooving the blocks.

A modification of this method is described, in which the slips are of the same length as the blocks, and the latter are connected together, at their inclined sides, by pegs d.

In figs. 5, and 6, the slips are fastened to two sides of each block, only, but they may be applied to all the sides, if preferred.

The patentee claims, firstly, the improvement in wood paving, whereby the blocks are cut and placed so that the central or stronger fibres shall always assist in supporting the external or weaker fibres; whereby, also, the blocks are arranged so as to break joint, and be bonded together continuously throughout at both surfaces; and whereby, also, the blocks are pegged together at the centres of both their vertical and sloped sides. Secondly, the improvement in wood paving, whereby the blocks are pinned or pegged together, by pins or pegs, at the centres of both their sloped and vertical sides, in the manner described, at whatever angle the blocks may be cut. Thirdly,—the improvement in wood paving, whereby blocks, cut at angles varying from 75° to 80°, are united together, by pegs, at their vertical sides, as above described. Fourthly,-the improvement in wood paving, by the use of two pegs, on the central line, as above described, of the vertical sides, whatever the angle of the blocks. Fifthly,-with respect to the third part of this invention, the improvements in wood paving, consisting in the modifications of arrangement and connection therein described. Sixthly,-the improve

ment in wood paving, by the use of slips of wood, or other elastic substance, between blocks, of whatever shape, for the purpose of affording a secure foot-hold.-[Inrolled in the Inrolment Office, January, 1843.]

TO RICHARD HODGSON, of Montague-place, in the county of Middlesex, Gent., for improvements in obtaining images on metallic and other surfaces.-[Sealed 7th July, 1842.]

THE first part of this invention relates to that class of optical instruments in which images are obtained upon suitable receiving surfaces, by means of reflecting mirrors; the improvement consists in causing the images, so reflected, to pass through a lens or lenses, interposed between the mirror and the receiving surface; and also, in passing the images through a tube or trunk, placed between the mirror and the receiving surface.

These improvements are shewn in Plate VI., at figs. 1, and 2. Fig. 1, represents a camera box, twelve inches in length, containing a reflecting mirror a, the surfaces of which are ground to different degrees of concavity; the silvered face being of sixteen inches radius, and the other face of ten inches radius. The object to be reflected upon the receiving surface is supposed to be the sun, or a star at an infinite distance, the rays from which are parallel, before reflection, and converge afterwards to the line b; but, by the interposition of an achromatic lens c, of eight inches focus, fastened in a tube d, the rays are made to converge to a focus at the point e. In passing through the achromatic lens, much of the spherical aberration is corrected, and the chromatic is greatly diminished.

In fig. 2, the mirror a, is the same as the one above described, and it is placed in a similar box; the object to be reflected is supposed to be at a distance of eight or ten feet. From the extreme points of the object, the rays ƒ, proceed, and, after reflection, would form a curved image of it on the line g; but, by interposing the correcting lens h, (which is a meniscus, of fourteen inches focus, fixed in the tube i,) the convergence of the rays is increased, and the image is formed upon the line j.

The patentee does not confine himself to the use of mirrors, having surfaces of unequal radii, as mirrors with parallel surfaces, or metallic mirrors, may be employed with