face of the steel, and render it as rough as if heated in a furnace or common fire. I am, Sir, yours, &c., WILLIAM WALKER, Q. H. Master. Lond. Mec. Mag.

Plymouth, October 12, 1847.

Specification of a Patent granted to PATRICK MOIR CRANE, of Yniscedwyn Iron Works, near Swansea, Iron Master, for Improvements in the Manufacture of Iron.-[Sealed, April 8th, 1847.]

This invention relates to an improvement in that part of the manufacture of malleable iron where what is called refinery iron is produced, by melting pig-iron in a refinery furnace; and it consists in a mode of employing anthracite or stone-coal in the process of making refinery iron. The patentee says he is aware that this has been before attempted, but without success, on account of the peculiar character of the anthracite or stone-coal, which is liable to decrepitate and fly off into dust on sudden exposure to heat; now, the present invention consists in subjecting the anthracite or stone-coal to heat, before introducing it into the refinery furnace. The preparatory heating may be effected in any convenient way: and the coal may be used either in an ignited or highly-heated state, or in a cold state (having been first ignited or highly-heated). After such preparation, the coal will bear either the hot or cold blast; and whichever blast be used, the patentee prefers that it should be introduced through two or more small tuyeres, instead of one large one. The refining process is conducted in the same manner as when coke or charcoal is used. In the manufacture of pig-iron by the aid of anthracite coal in the blast furnace, a considerable quantity of highly-heated anthracite coal comes from the furnace in lumps, in that process commonly termed by the workmen "throwing off;" and the patentee either introduces these lumps in a heated state into the refinery furnace, or he preserves them for future use. Or, instead of employing these lumps, the patentee causes the raw anthracite coal to be ignited in masses in pits, kilns, or ovens, and, when thoroughly ignited and heated, he carries it direct to the refinery furnace, or preserves it for future use. Although the patentee has used the anthracite coal alone, other fuel may be employed therewith.

The advantages said to result from the use of anthracite coal, according to this invention, are,-that a considerable saving is effected in comparison with the coke of bituminous coal-the cinder contains less iron than that from a refinery furnace worked with the coke of bituminous coal-and in those districts where anthracite or stone-coal can alone be obtained, manufacturers of iron will now be able to refine their iron, which has not hitherto been the case.

The patentee claims, as his invention, "applying, in the manufacture of refinery iron, anthracite or stone-coal, which has been ignited or raised to a high temperature, before introducing it into the refinery furnace."-Inrolled, October, 1847. Lond. Journ. Arts & Sci.

Manufacture of Alkali and Chlorine.

Mr. C. T. Dunlop, of Glasgow, has recently obtained a patent for some improvements in the inanufacture of alkali and chlorine, and in the application of the product resulting therefrom;" the first part of which consists in an improved method of producing chlorine, fit for manufacturing purposes, by the mutual decomposition of the following substances:-Muriate of soda, or any other muriate-nitrate of soda, or any other nitrate-muriatic acid-nitric acid. In some instances it is also requisite to use sulphuric acid; and the patentee generally prefers to employ it, in order to obtain, as a residual product, sulphate of soda, suitable for the manufacture of soda, &c. All the above materials may be employed together, or only two of them; as, for instance, a nitrate with a muriate (in which case sulphuric acid must also be used), or a muriate with nitric acid, or a nitrate with muriatic acid, or muriatic acid with nitric acid; in the latter cases, sulphuric acid is employed, according to the results desired to be obtained. The patentee says he does not confine himself to any proportions, but the process he usually adopts is, to bring together common salt, nitrate of soda or nitric acid, and sulphuric acid, in suitable proportions; heat being then applied, chlorine, an oxide of azote, and muriatic acid, are evolved; these gases are caused to pass through a condeuser, charged with sulphuric acid, of sufficient strength to absorb the oxide of azote; and then the chlorine and muriatic acid are separated by means of water. The second part of the invention relates to the application of the product resulting from the above process, and consists in the production of nitric acid from the sulphuric acid, charged with oxide of azote, which is true nitrous sulphuric acid. This is effected by the aid of atmospheric air, steam, and water; and the process adopted by the patentee is, to introduce the nitrous sulphuric acid into a suitable vessel, and, by the addition of water and heat, to effect the disengagement of the oxide of azote, which, being caused to traverse a condenser, together with a sufficient quantity of air and steam, or water, is by this means transformed into nitric acid: this acid may be again used in the manufacture of chlorine, and again recovered, and so on. Sometimes, in place of treating the nitrous sulphuric acid, as just described, the patentee causes the oxide of azote to be evolved, and to pass into a chamber, into which a current of sulphuretted hydrogen is streaming; by which means sulphate of ammonia is obtained and sulphur deposited. The patentee claims the manufacture of chlorine from the materials above mentioned, in the manner described; the process employed for separating the gaseous products, so as to obtain the chlorine in a sufficiently pure state for manufacturing purposes; and the two processes described for utilizing the products resulting from the manufacture of chlorine. Lond. Min. Journ.

Improvements in Casting Cylindrical Pipes.

Mr. D. Y. Stewart, of Montrose, has taken out a patent for a new

mode of casting iron, water, or gas pipes, or other cylindrical tubes; by which a far more superior material is produced, at a much less cost than by the usual method. The mould consists of a perpendicular cylindrical iron box, of the required size, with a shaft in the centre, longer than the mould, and communicating with machinery above, by which it is kept revolving, and, as it revolves, it gradually rises. At the bottom of this shaft is an instrument. which may be termed a "presser," or "rammer," consisting of an iron block, having inclined tabular faces, of such smaller diameter than the box, as to leave the sand of the required thickness for the mould. On feeding the sand at the top of the box, it is distributed towards the sides, and the shaft and raminer, gradually revolving and rising, press it with great force against the side of the box, leaving the mould finished and perfectly cylindrical on its arriving at the top, ready for the insertion of the core. The amount of pressure against the sand is regulated by means of a counterpoise weight. The following are the advantages claimed by the patentee:"1. A perfectly straight cylindrical pipe, of uniform thickness.-2. No parting or joint of any kind.-3. Dressed at one-half the ordinary cost.-4. Less sand used than in any other way, and, of course, easier dried, if required.-5. The castings and sand easier removed from the boxes than in the ordinary way.-6. The flasks, or boxes, better calculated to resist the pressure of the metal than any now in use.-7. This method is the best for casting pipes perpendicularly that has hitherto been employed.-8. The greatest recommendation of all is, the simplicity of the apparatus, which requires the attendance of a boy only, who with my machine, as at present working, turns out easily six pipes, six inches bore, per hour." We understand that two miles of water-pipes have been laid by the patentee at Montrose, and the Town-Council passed him a vote of thanks. Some capitalists have joined the patentee, forming a company, and ground has been secured in Glasgow, where premises will be erected for carrying on the business on a large scale.

Lond. Min. Journ.

On a New Process of Engraving, called Stylography.

A new method of engraving has been invented by M. Scholer, a native of Denmark. In 1842, M. Scholer had so far perfected his invention as to produce satisfactory results, which were submitted to the King of Denmark, who rewarded the invention on the condition of his publishing a complete description of his method. In conformity with this agreement, he has just published the particulars of the process at Copenhagen, and has also made it known at Bruxelles. The Academy of Sciences of this latter city approved of it in its sitting of the 4th December, 1846. M. Buschman d'Aurey subsequently made use of it at Antwerp, and, on the 18th of last May, his experiments were submitted to the Academy at Bruxelles.

One part of copal, three of stearine, and three of lac are melted together, and a sufficient quantity of Frankfort black is added to render

the composition black. The whole is melted in a mould about six lines (or half an inch) in depth, formed of two sheets of copper, which are first rubbed over with an amalgam of tin, and whiting and Tripoli, blackened over the flame of a lamp. The sheet of composition is then to be taken from the mould; it will come out easily, and will harden on contact with the air. It is afterwards to be rubbed with a solution of resin in spirits of wine, and polished; and before it is quite dry it is to be covered with silver powder, until it is like a sheet of white paper. The design is then to be counter drawn on it in red, and the whole is to be gone over with a dry-point or graver, the different shades being regulated by cutting to greater or less depths, and varying the width of the lines as well as the distances between them.

The design being engraved, it is to be cleansed with water, and covered with a solution of sugar mixed with a small quantity of nitrate of silver, and bronze powder laid on with a brush.

It then only remains to apply the known processes of galvanoplastics: first, a plate is formed in relief, and from that the plate is produced which is to be printed from, in the same manner as etched or engraved plates. The principal advantage of M. Scholer's process is a saving of labor to the engraver, as he draws in black on a white ground, in the same manner as with pencil and paper.

The results hitherto obtained, although satisfactory, must be merely regarded as slight indications of what may be done by this process in the hands of skilful artists, when some apparent difficulties incident to all new industrial processes (such as lithography, for instance) shall have been made to disappear by practical experience.

If, however, M. Schoeler's process does away with some disadvantages which are frequently encountered in the ordinary process of etching, and which are unfavorable to the production of good engravings, it necessitates an extra operation (that of electrotyping) which Occasions a certain expenditure of time and money; but it is not unreasonable to suppose that by experience some improvement will be effected in this part of the process. It is not likely that Stylography will ever rival line-engraving in beauty; but it possesses over it the advantage of not requiring for its execution one-tenth part of the time: and, moreover, by this means the artist may himself engrave his design with even greater facility than it could be lithographed; which is a great advantage, when he wishes to produce a great number of copies of his work.

M. Scholer has sent thirteen specimens of his works to the Royal Academy at Bruxelles, consisting of two landscapes, three studies of heads, portraits of Frederick VI. and Beethoven, portraits of Lord Byron at several periods of his life, and five finished studies of heads, amongst which, an oriental study, about four inches high, is a very excellent specimen, as the finest and most delicate lines, produced by the point, are well brought out. Several of these specimens have the fault of too much vigor, or rather perhaps too much hardness and dryness; a very skilful hand being required to handle the point lightly, and to produce effective shadowing; but this is easily acquired by ar

tists, as will be seen from the perfection which has been arrived at in lithography.-Bulletin de la Societé d'Encouragement.

Lond. Journ. Arts & Sci.

Extracts from Proceedings of Cornish Scientific Meetings. Apparatus for ascertaining the specific gravities of bodies expeditiously. This was invented by Mr. R. W. Fox, who said that, in visiting Wales a month or two ago, it appeared to him that it would be important for the iron smelters there (buying as they do Cornish and other kinds of ore), to have some apparatus for easily ascertaining the specific gravity of ores, that having reference to their richness. He had since then constructed a little apparatus for weighing quantities. The principle depends upon the weight of water displaced, as indicated by an external graduated tube, the amount of the displacement being the divisor of a body weighed in air. The apparatus is also capable of acting as a balance by the use of a close cylinder, which by sinking in the water raises the water in a tube carefully graduated; so that, when the water is brought to the zero point, every substance put into the cylinder of any kind, and however divided, will have its weight indicated in the tube. The apparatus is applicable to weighing ores of all kinds, and to detecting the presence of any metallic substance in stony matter. For instance, he knew the specific gravity of quartz or slate, and, if it exceeded that, he should suspect there was some metallic matter in the stone, and the weight would show the amount of metallic matter. He believed it would ascertain the specific gravity to the third figure of decimals. The adjustment of the zero is easily accomplished by a little cock below the tubes, and the construction of the apparatus is very inexpensive.—Mr. Fox, in giving a further account of this instrument on the following day, said he could weigh substances, whether iron, manganese, tin, or any kind of ore, of which he wished to obtain the specific gravity, that having always reference to its richness. He might first weigh it in a common balance, or he had the means of weighing it by the water balance in the instrument itself. After stating the manner in which he had carefully graduated the scale, he weighed some quartz pebbles by means of the instrument, which amounted to 2560 grains-this being the same, he stated, as if they had been weighed in a common balance. He next weighed the same pebbles in water, the difference between that and the weight in air giving the specific gravity. The weight in water was 1050 grains, which being used as a division of the weight in air, 2560 grains, gave the specific gravity as 2.438, or nearly two and a half heavier than water. The instrument, he said, was capable of testing the weight, as compared with water, of any earthy substance, of soils, or of any lighter substances than water, by pressing them down. He thought that, for testing the specific gravity of tin, iron, or manganese ores, the utility of the instrument to miners may be very considerable.-Mr. John Taylor spoke of the benefit that must result from the use of such an instrument as that invented by Mr.