Description of two recent inventions of artificial stone, with remarks
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dlrti ficial ,Stone. 28 7 ple, but effective contrivance. A piece of tit], bent into the form of art inverted cone, is soldered inside the lid, which causes the hot ascending air to flow towards the sides, where it immediately escapes througl~ the openings. To prevent any inflammable gas enterittg through the lid, a circular disk of wire gauze is soldered inside the rhn of the lid--- so that no gas can enter but through the wire gauze; this wire gauze will never become red-bet, so that no explosion can possibly occur. The size of lanthorns made is about 5 inches square, and 1~ inches high; other parts in proportion. The iuside of the tin eoversides, and the outside of the lantborn, are japanued of any dark color. Cir. Eng. & Arch. Journ., Aug., 1848. Description oJ' Two Receipt lnven/ion,~ of ~lrtifieial Stone, with Remarks bou Ma. FAnAI)A~'. Mr. Faraday said that, in undertaking at a short notice to describe the principles on which those artificial stones were constructed, he refrained from expressing an opinion as to their probable commercial success. He explained tile process adopted and the object aimed at, first it] Mr. Ransome's, and afterwards iu Mr. Buckwell's inventiou. Broken flitrts are dissolved in a solution of caustic alkali at a tem- perature of :300 ° Fabr. Whet] this solution is sufficiently evaporated, siliceous sand, or the flint grit of roads, and a little clay are worked with it, till the whole is of the consisteuee of putty. It is firtally pressed in moulds, dried, fired for 48 hours, and then slowly cooled. The impressiot] produced is very sharp ; the stone resembles white sand. stone, and is said to resist all atmospheric changes, attd even acids. Philosophically considered, this artificial stone is a mass of sand ce- mented togetfier by glass. The glass, at first containing excess of alkali, is diffused in a fluid state throughout the particles of flint and alumina. These particles absorb the superabtmdant alkali whet] the stone is fired, and the resulting vitreous cement resembles, in hard- ness and resisting power, the portion of glass which, in the common matmfaeture of the hardest kinds of that substance, is found in im- mediate contact with the sides of the pots. To show the unstable nature of ordinary glass, Mr. Faraday exhibited green bottles in which diluted sulphurie aeid had been kept. lu the glass of these bottles the lime had been separated from the silica by the sulphurie acid, and the insides were in consequence studded with multitudes of regularly- for:ned cones of sulphate of lime. Mr. Faraday then entered on Mr. Buekwell's manufacture. .As the artificial ~tone invented by Mr. Ransome i.,s chiefly applicable for ornamental purposes, so Mr. Buck- well's invention, termed by him artificial granite, appears exclu- sively designed to supply tile place of blocks brought from the quarry for large works, whether walls of houses or of aqueducts, sewers, &e. Mr. Buekwell uses the following simple proeess:--Fragments of a suitable stone (Portland stone, for example) are gauged and sorted into sizes. These are cleaned and carefully mixed on a board with cement in the proportion of 5 parts of large fragments, 2 of smaller ones, 1 of cement, and a portion of watcr,--but the water is in no
Transcript of Description of two recent inventions of artificial stone, with remarks
dlrti ficial ,Stone. 28 7
ple, but effective contrivance. A piece of tit], bent into the form of art inverted cone, is soldered inside the lid, which causes the hot ascending air to flow towards the sides, where it immediately escapes througl~ the openings. To prevent any inflammable gas enterittg through the lid, a circular disk of wire gauze is soldered inside the rhn of the lid--- so that no gas can enter but through the wire gauze; this wire gauze will never become red-bet, so that no explosion can possibly occur. The size of lanthorns made is about 5 inches square, and 1~ inches high; other parts in proportion. The iuside of the tin eoversides, and the outside of the lantborn, are japanued of any dark color.
Cir. Eng. & Arch. Journ., Aug., 1848.
Description oJ' Two Receipt lnven/ion,~ o f ~lrtifieial Stone, with Remarks bou Ma. FAnAI)A~'.
Mr. Faraday said that, in undertaking at a short notice to describe the principles on which those artificial stones were constructed, he refrained from expressing an opinion as to their probable commercial success. He explained tile process adopted and the object aimed at, first it] Mr. Ransome's, and afterwards iu Mr. Buckwell's inventiou. Broken flitrts are dissolved in a solution of caustic alkali at a tem- perature of :300 ° Fabr. Whet] this solution is sufficiently evaporated, siliceous sand, or the flint grit of roads, and a little clay are worked with it, till the whole is of the consisteuee of putty. It is firtally pressed in moulds, dried, fired for 48 hours, and then slowly cooled. The impressiot] produced is very sharp ; the stone resembles white sand. stone, and is said to resist all atmospheric changes, attd even acids. Philosophically considered, this artificial stone is a mass of sand ce- mented togetfier by glass. The glass, at first containing excess of alkali, is diffused in a fluid state throughout the particles of flint and alumina. These particles absorb the superabtmdant alkali whet] the stone is fired, and the resulting vitreous cement resembles, in hard- ness and resisting power, the portion of glass which, in the common matmfaeture of the hardest kinds of that substance, is found in im- mediate contact with the sides of the pots. To show the unstable nature of ordinary glass, Mr. Faraday exhibited green bottles in which diluted sulphurie aeid had been kept. lu the glass of these bottles the lime had been separated from the silica by the sulphurie acid, and the insides were in consequence studded with multitudes of regularly- for:ned cones of sulphate of lime. Mr. Faraday then entered on Mr. Buekwell's manufacture. .As the artificial ~tone invented by Mr. Ransome i.,s chiefly applicable for ornamental purposes, so Mr. Buck- well's invention, termed by him artificial granite, appears exclu- sively designed to supply tile place of blocks brought from the quarry for large works, whether walls of houses or of aqueducts, sewers, &e. Mr. Buekwell uses the following simple proeess:--Fragments of a suitable stone (Portland stone, for example) are gauged and sorted into sizes. These are cleaned and carefully mixed on a board with cement in the proportion of 5 parts of large fragments, 2 of smaller ones, 1 of cement, and a portion of watcr , - -but the water is in no
288 Meehanle~, Phgsics, and Chemistrgt.
greater quantil9 than will bring it to tile dampness of fresh deal s.~w- dust. This being done, the materials are put into a strong mould to the depth of 1~ inch at a t ime; they are then driven logether bgTer- cus, ion, more materials are now put in, these in turn hammered to- gether till the water has escaped by holes pierced for that purpose in the moulds,--and this process is continued till the block or pipe has attained the required magnitude. It is then taken out of the mould, and now found to be so hard as to ring when struck, and in ten days is fit for service. It is affirmed to harden under the influence of mois- ture, to bear, when moulded in the form of girders, a greater trans- verse pressure than any rock except slate, and to be only one-sixth of the cost of brick-work. It will be noticed that this process is charac- terized by the use of t?agments, by the small quantity of cement em- ployed, (not one-fourth of the proportion used in common grouting,) and by water, instead of fire, being made the means of bringing the fragments into close union. Mr. Faraday then noticed two scientific principles on which the success of Mr. Buckwell 's process greatly de- pends : ~
1. The use of water in effecting the a~oproximalion of the Tarli- eles and the exclusion of air.--lt had been ascertained by Dr. Wol- laston (Bakeriau Lecture, 1828) that in order to bring tile particles of platina i~to close contact, it was best to bring them together in water. When a freshly made road is watered to mak.e the materials bind together, the same principle assists m the result. Having filled a measured glass with sand° Mr. Faraday showed that when the glass was first filled with water and then the sand added with agitation, it occupied less space than it did when dry.
2. The effect of percussion in bringing particles together. Mr. Faraday noticed, that simple pressure will not displace intersticial air or water, but that a blow will. Water contained in a small cylinder of wire-gauze was shown remaining in the open net-work when sub- jeeted to tile pressure of a column of the same fluid, though it freely ran through the meshes when the cylinder was gently struck. On the same principle the moistened sand on the sea shore gives way, and leaves a footmark under the impact of the limb which strikes it. In conclusion, Mr. Faraday noticed the remarkable fact that the sedi- mentary matter in sewers, &e., does not accumulate on Mr. Buck- well's artificial granite as it does in glc.zed pipes.--Proc. Roy. Inst.
London Athenmum, June, 1848.
Russian Monolith.
The Journal of the Polytechnic Society for October, 1847, notices a stone quarried in Russia, under the direction of M. Monferrard, a French Architect, for the purpose of erecting a statue of the Emperor Alexander. The block is 30 metres (98.45ft.) in length, by 7 metres (22"97 feet)square, and the weight is estimated at 4,700,000 kilo- grammes (4626 tons). It required the labor of 600 workmen for two years to prepare it, and 80 iron capstans and 2000 men were employ- ed in its erection.
