taken vertically through the melting furnace a, a, a, a ;— b, representing the bridge, which separates the fire from the materials; c, the grate-bars; and d, the ash-pit.

The

raw material or cullet is placed upon the inclined bottom of the furnace at e, which, when it is fluxed, flows through the fire-clay tube f, into the pot g, also placed in and heated by the furnace; an additional fire-place, for heating the pot, is shewn at h.

Fig. 2, is a plan view of a grinding-machine, exhibiting the improved arrangement of the grinding-benches or beds. a, a, represents the fly-frame; b, b, elbow-cranks, in the foundation; c, c, elbow-cranks, in the fly-frame; d. d, connecting-rods, with mortices, to allow the rummers or rubbers e, e, which contain the top glasses, to slide in; f,f, stone tables, for the undermost glasses to rest on; g, g, centre-pins and slots, for adjusting the rummers e, e; and h, h, the hinges of the connecting links d, d, and the flyframe a, a; the whole of which is driven by the main driving-crank at b*.

Fig. 3, represents a side elevation of a machine, for polishing plate-glass, with the improved arrangement of the polishing-bars. The bed or main framing of the machine is shewn at a, a, supporting the slate-frames b, on which the plates of glass to be polished are laid, and to which the traverse-motion is applied as usual. c, c, represents one of a series of four polishing-bars, with the rubbers d, d, which are caused to travel to and fro, alternately, as usual, upon the rummers e, e, being actuated by cranks and connecting-links f, f, which will also be readily understood.

The patentee claims, firstly, the fluxing of the raw materials or cullet, in a reverberatory furnace, in the first instance, by the direct application of the heat upon them, without the intervention of a pot or vessel in which the materials are fluxed, without being in any way confined in its application to the particular form of furnace, shewn in the drawing; secondly, placing four grinding-benches, with their rummers all put in motion, with their fly-frame, by one driving-crank in the grinding-machine; thirdly, having

additional polishing-bars, as above described, with reference to the polishing-machine.-[Inrolled in the Petty Bag Office, September, 1840.]

Specification drawn by Messrs. Newton and Son.

To HENRY SCOTT, of Brownlow-street, Bedford-row, surgeon, for improvements in the manufacture of ink or writing fluids.-[Sealed 31st December, 1840.]

THIS invention consists in a peculiar mode of making ink, by the use of nitrate of iron and gas-black.

In the first place, forty-eight pounds of logwood chips are soaked in soft water for two days, and at the end of that time are boiled, for an hour and a half, in a close cauldron, with eighty gallons of soft water; they are then taken out, and forty-eight pounds of coarsely-pulverised Aleppo galls added to the liquid, which is then boiled for an hour longer. The liquid now remains for twenty-four hours, (being stirred at intervals,) and the clear portion of it, being drawn off, is mixed with forty pounds of sulphate of iron, in the state of powder; this mixture is allowed to stand for a week, being stirred daily, and then an addition is made to it of four gallons of vinegar. After this, about seven pounds and a half of gum arabic, dissolved in a small quantity of water, are incorporated with the mixture; and when a few days have elapsed, twenty ounces of nitrate of iron are added. When the mixture has become sufficiently black, the clear liquor is drawn off, and mixed with three pastes or compositions; the first of which is made by grinding half a pound of Spanish indigo in some of the ink before mentioned; the second, by grinding three pounds of Prussian blue in distilled water; and the third, by grinding four ounces of gas-black in one ounce of nitrate of iron. The ink, thus made, is stirred daily for a week, and at the end of that time the clear liquor is drawn off, ready for use. The proportions, herein mentioned, will make eighty gallons of ink.

The patentee claims, as his invention, the application of nitrate of iron and gas-black, when combined with other suitable materials, in the manufacture of ink.~[Inrolled in the Inrolment Office, June, 1841]

To JOHN SWINDELLS, of Manchester, in the county of Lancaster, manufacturing chemist, for certain improvements in the manufacture of artificial stone, cement, stucco, and other similar compositions.—[Sealed 6th January, 1841.]

THESE improvements consist in rendering certain residual matters, (produced in various chemical manufactories,) available for the manufacture of cement.

The materials to be used in the manufacture of the lithic or stone cement, are the residuum arising from the manufacture of the chromates and bi-chromates of potash and soda, or other chromic salts, which residuum consists of oxide of iron, silicate of alumina, lime, sulphate of lime, and some undecomposed chromate of iron. If the lime, in this residual matter, does not amount to fifty per cent., other lime is added until it contains that quantity; if the silicate of alumina, contained therein, does not amount to thirty per cent., silicate of alumina, to that amount, is added. Any of the common clays will answer the purpose. These various materials are then calcined in a furnace or kiln, similar to burning limestone for the production of lime; after which, the compound is pulverised to a fine powder, and packed in tight casks, ready for use.

To make coarse cement, commonly called Roman cement, residuum, produced in the manufacture of potash, soda, or British alkali, commonly called soda-ash, is used; this residual matter is known by the name of vat-waste, and remains after the lixiviation of the alkaline salts. It consists chiefly of lime, contained in the waste sulphurate, and carbonate of lime, with various preparations of carbonaceous matters. To this residuum, silicate of alumina or any other common

clay, is added, in the proportion before stated; namely, thirty per cent. of the silicate, to as much vat-waste as contains fifty per cent. of lime; and to this is added twenty per cent. of oxide of iron, or the same quantity of oxide of manganese and iron, the oxide of iron being obtained from the residual matter, produced in making sulphuric acid from the bi-sulphurate of iron, commonly called pyrites or mundic. The oxide of manganese is obtained from the residual salts of manganese, produced in the manufacture of chloride of lime or other chlorine salts.

The method pursued in manufacturing the cement from these materials, is thoroughly to mix them together in the proportions already stated,-then to calcine them in the same way as the burning of lime, and when cold to pulverise the compound into a fine powder, and pack up the same into tight casks, ready for use.

The patentee claims, firstly, the use of the residuum, produced in the manufacture of chromic salts, for the manufacture of lithic or stone cement, or artificial stone; secondly, the use of the residual matters, produced in the manufacture of potash, soda, British alkali, or soda-ash, commonly called vat-waste, and the residual oxide of iron, produced in the manufacture of sulphuric acid from the bi-sulphurets of iron, commonly called pyrites or mundic; and thirdly, the use of the residual oxides of manganese, produced in the manufacture of chloride of lime or other chlorine salts, for the purpose of manufacturing stucco or Roman cement.-[Inrolled in the Petty Bag Office, July, 1841.]

Specification drawn by Messrs. Newton and Son.

TO HENRY KIRK, of Tavistock-square, in the county of Middlesex, Gent., for a substitute for ice for skating and sliding purposes.-[Sealed 2nd November, 1841.]

THIS invention consists in the production of a composition, having a smooth surface, similar to ice, over which persons may skate and slide, at any season.

The artificial ice is cast or formed into slabs, and then laid down upon a floor, under cover; a portion of the same substance, of which the slabs are composed, being melted and used for cementing them together; or the artificial ice may be cast upon the floor, being poured thereon in a melted state. The floor must be perfectly air-tight, and impervious to the wet, which can be effected by covering it with thin plates of zinc or lead; or it may be made of stone, concrete, or asphalte.

The ingredients, that compose the artificial ice, belong chiefly to that class of chemical substances called salts, being chosen from among those salts that contain the largest proportion of water of crystallization, and which are therefore capable of being dissolved, by the method. called watery fusion. The salts preferred, on account of their cheapness, are alum and the carbonate, sub-carbonate, and sulphate of soda; another substance, used in one mode of preparing the artificial ice, is sulphur.

The mode of operation, when alum is used for producing the artificial ice, is as follows:

Ten pounds of crystallized alum is crushed into powder, and melted in a copper, and when in a liquid state, threequarters of an ounce of sulphate of copper are added, for the purpose of colouring it; an addition is also made of one pound of hog's lard, to render it more slippery. This mixture, after it has cooled a little, is ready to be cast into slabs.

When the carbonate or sub-carbonate of soda is used, ten pounds of either of them, in the state of crystals, are reduced to a coarse powder, and melted; the action of the heat being continued, until, by the gradual evaporation of water from the melted salt, it has lost one-fifth of its weight. Three-quarters of an ounce of sulphate of copper, or a small quantity of "chemic blue," may now be added to the melted salt, to give it a colour; and the mixture, after being allowed to cool, is formed into slabs.

Sulphate of soda is converted into artificial ice, in the same manner as the carbonate or sub-carbonate of soda.

The same operation is performed when the artificial ice