TO ERNST WOLFF, formerly of Stamford Hill, in the county of Middlesex, but now of Camberwell, in the county of Surrey, merchant, for a certain improvement or certain improvements in steam-engines,—being a communication from a foreigner, residing abroad.— [Sealed 26th April, 1834.]

THIS invention consists in employing steam to work two or more engines successively, and thus compel it to expend all its elastic force before escaping into the atmosphere.

The first of the engines must be worked under high pressure; the second and following, are low pressure engines. Steam, passing from the boiler, in a state of high pressure, into the cylinder of the first engine, acts upon the piston, and then proceeds through an eduction pipe into the cylinder of the second engine; or else into an outer jacket of the same, and thence into the cylinder; and, after acting upon its piston, passes off into the condenser, or escapes into the atmosphere. If there be a third engine, the steam proceeds into the working cylinder,—acts upon its piston, and then passes to the condenser, or into the atmosphere.

In place of the steam passing from the cylinder of the first engine, into the outer jacket of the cylinder of the second engine direct, it may be better for it to pass through a separate steam-chamber, in which the pressure of the steam may be raised, by heating the said chamber by a separate fire; or fresh steam may be blown into it from the boiler; and an auxiliary quantity of steam may be passed into the cylinder of the second engine, direct from the boiler, in case the boiler generates more steam than is required to work the first engine at a high pressure.

The power of these engines may be applied to turn the same or different crank shafts, at one time.

The patentee claims the invention above described, by

which the same steam is made to act upon two or more engines in succession, so that a greater degree of power may be obtained from the same quantity of steam.-[Inrolled in the Inrolment Office, October, 1834.]

This plan of economising steam has been several times introduced to the public in previous patents.-See Uding's, for improvements in steam-engines, Vol. IV., page 191, of our Second Series.-ED.

TO JAMES HARVEY, of Basing-place, Waterloo-road, in the county of Surrey, timber merchant, for certain improvements in paving streets, roads, and ways, with blocks of wood; and in the machinery or apparatus for cutting or forming such blocks.-[Sealed 2nd June, 1840.]

My invention of improvements in paving streets, roads, and ways, with blocks of wood, consists, in the first place, in the adaptation of certain novel shapes or configurations, forming blocks of wood, to be applied to paving; and secondly, in an improved machine, whereby I am enabled to cut and form blocks, to the required shape, in a quicker and more economical manner than has heretofore been done.

In order that my invention may be fully understood, I have annexed to these presents, drawings explanatory of the different shapes of blocks I intend to use, in paving streets, roads, and ways; and also several views of the machinery I employ for forming certain of the blocks therein shewn.

The figures in Plate II., represent the forms of various shaped blocks, which I employ for the purpose of paving. Figs. 1, 2, 3, and 7, are different views of one block; figs. 4, 5, 6, and 8, are similar views of another or companion block, which, when put together, support each other.

Fig. 1, represents one of the blocks, as it would appear if seen cornerwise; fig. 2, shews the flat side of the same; and fig, 3, is the reverse side, exhibiting that surface of the block which is indented or formed into two equal pyramids.

Fig. 4, is the fellow or companion block to the one just described, and represents its angular side, formed by two pyramids, in a similar view to that shewn at fig. 1; fig. 5, is a view of the flat side of the block, corresponding with the position shewn at fig. 2; fig. 6, is the reverse side of the same, corresponding to the view shewn at fig. 3; and figs. 7 and 8, are end views of the two blocks, seen in perspective.

Figs. 9 and 10, represent an elevation and horizontal view of four blocks combined; that is,-two pairs placed together, and fitting into each other.-These blocks, when combined to form a pavement, are so arranged that they support each other, as, from their double-wedged shape, no one block can rise without disturbing those that are contiguous. Figs. 11, 12, 13, and 14, are views of another block, which is produced from a cylinder, cut into six sections through its axis, so as to form wedges, the sides of which subtend angles of 60°.

Fig. 11, is an elevation of a single block of the above form, presenting its curved face; and fig. 12, is a plan view of the same.

Fig. 13, is an elevation of several of these blocks, in connection; and fig. 14, is a plan view of the same.

Figs. 15 and 16, represent the plan and elevation of a continuation of several blocks of another shape, which may be described as consisting of segments of a cylinder, cut parallel to the axis, in a meniscus form; fig. 15, shews an elevation of two of these blocks; and fig. 16, is a plan or horizontal view of four of these blocks, arranged as they would be when laid down for the pavement of a road. It

will be seen, that these segments are set upright, in alternate rows; the one row presenting the concave surface, and the other row the convex surface, so as to afford a convenient holding for the feet of horses.

Fig. 17, represents an elevation of two blocks of another form, and fig. 18, is a plan view of the same. This block may be described as an oblong four-sided prism, having each of its extremities bevelled off in parallel planes, at oblique angles to the sides. These blocks, when laid down, are arranged in the manner represented at fig. 19, which is a horizontal view of a portion of each row of blocks, tending to support one of the contiguous rows, whilst it is itself supported by the other row, with which it is in contact.

Figs. 20 and 21, represent a side elevation and plan of another block, which is shaped as the last described, but has a rebate cut in each of its acute angles. Fig. 22, exhibits two of these blocks, placed in contact, as laid down for paving.

Figs. 23 and 24, are a top view or plan and elevation of another shaped block, formed as if two oblong four-sided prisms were each cut off at one of their angles, and conjoined to constitute one block.

Figs. 25 and 26, are similar views of another block, which may be described as a four-sided prism, having angular recesses cut in two of its corners, half way down, and similar recesses cut in the other two corners, half way up, so as to constitute rebated edges. When these blocks are employed for paving, by their peculiar shapes and ledges, they both support and are supported by the surrounding blocks, so that the pavement being completed, by the combination of several blocks, no one block can be withdrawn without disturbing the others. The plan, fig. 27, shews the manner of connecting them.

Fig. 28, represents, in elevation, a modification of the last-described block; but, in this instance, cut out of a cylinder instead of a cube; fig. 29, is the horizontal view of the same; and fig. 30, shews the manner in which several of these blocks are to be combined to constitute a pavement.

Figs. 31, 32, and 33, exhibit another peculiarly shaped block, which, from its wedge-form, may also be called selfsupporting, as each block bears up the two contiguous blocks. These may be geometrically described as parallel rectangular blocks, on their upper and lower surfaces, but wedge-shaped at the sides, having the grain or fibres of the wood placed obliquely. The upper surface of the conjoined beams may be ribbed with parallel grooves, about one-fourth the width of the smooth portions, for the horses' feet to hold by.

Fig. 31, is a side elevation of two blocks, placed together; fig. 32, is an end elevation of the same; and fig. 33, is a horizontal view of the two blocks, as laid down for paving.

It will be perceived, that the sides of the block a, gradually taper towards the base, but the ends gradually taper towards the summit. The reverse, however, is the case with the block b; for the sides of this block gradually taper towards the summit, while the ends thereof taper towards the base.

From this description it will be evident, that the block a, is supported by the block b, by resting on its inclined sides; and the block b, will be supported, at its ends, by two blocks, similar in shape to the block a; thus, each block supports and is supported by the adjoining blocks, with which it is in contact, as above described.

Figs. 34 and 35, represent a block in the form of a cross, all the sides being equal, and at right angles with each other.

If considered necessary, the upper edges of the