pressed together, as closely as possible, so as to leave as little as may be of the cement between them. This is a general rule in cementing, as the thinner the stratum of cement interposed, the firmer it will hold. Melted brimstone, used in the same way, will answer sufficiently well, if the joining be not required to be very strong. 87 warm it; and it will join marble, stone, or earthenware, so that the joining is scarcely to be discovered. Boiled linseed oil, litharge, red lead, and white lead, mixed together to a proper consistence, and applied on each side of a piece of flannel, or even linen or paper, and put between two pieces of metal before they are || brought home, or close together, will make a close and durable joint, that will resist boiling water, or even a considerable pressure of steam. The proportions of the ingredients are not material, but the more the red lead predominates, the sooner the cement will dry, and the more the white lead the contrary. This cement answers well for joining stones of any dimensions. || The following is an excellent cement for iron, as in time it unites with it into one It sometimes happens that jewellers, in setting precious stones, break off pieces by accident; in this case they join them so that it cannot easily be seen, with gum mastic, the stone being previously made hot enough to melt it. By the same medium cameos of white enamel or colored glass are often joined to a real stone as a ground, to produce the appearance of an onyx. Mastic is likewise used to cement false backs or doublets to stones, to alter their hue. The jewellers in Turkey, who are gene-mass :-Take two ounces of muriate of amrally Armenians, ornament watch-cases and monia, one of flowers of sulphur, and 16 other trinkets with gems, by gluing them of cast-iron filings or borings. Mix them on. The stone is set in silver or gold, and well in a mortar, and keep the powder dry. the back of the setting made flat to corres- When the cement is wanted for use, take pond with the part to which it is to be ap- one part of this mixture, twenty parts of plied. It is then fixed on with the follow-clear iron borings or filings, grind them toing cement. Isinglass, soaked in water gether in a mortar, mix them with water to till it swells up and becomes soft, is dis- a proper consistence, and apply them besolved in French brandy, or in rum, so as tween the joints. to form a strong glue. Two small bits of Powdered quicklime mixed with bullock's gum galbanum, or gum ammoniacum, are blood is often used by coppersmiths, to lay dissolved in two ounces of this by tritura-over the rivets and edges of the sheets of tion; and five or six bits of mastic, as big as peas, being dissolved in as much alcohol as will render them fluid, are to be mixed with this by means of a gentle heat. This cement is to be kept in a phial closely stopped; and when used, is to be liquefied by immersing the phial in hot water. cement resists moisture. ure. A solution of shell lac in alcohol, added to a solution of isinglass in proof spirit, makes another cement that will resist moistSo does common glue melted without water, with half its weight of resin, with the addition of a little red ochre to give it a body. This is particularly useful for cementing hones to their frames. If clay and oxide of iron be mixed with oil, according to Mr. Gad, of Stockholm, they will form a cement that will harden under water. copper in large boilers, as a security to the junctures, and also to prevent cocks from leaking. Six parts of clay, one of iron filings, and linseed oil sufficient to form a thick paste, make a good cement for stopping cracks in iron boilers. This Temporary cements are wanted in cutting, grinding, or polishing optical glasses, stones, ||and various small articles of jewellery, which it is necessary to fix on blocks, or handles, for the purpose:-Four ounces of resin, a quarter of an ounce of wax, and four ounces of whiting made previously red-hot, form a good cement of this kind; as any of the above articles may be fastened to it by heating them, and removed at pleasure in the same manner, though they adhere very firmly to it when cold. Pitch, resin, and a small quantity of tallow, thickened with brick-dust, is much used at Birmingham for these purposes. Four parts resin, one of bees-wax, and one of brick-dust, likewise make a good cement. This answers extremely well for fixing knives and forks in their hafts; but the manufacturers of cheap articles of this kind, too commonly use resin and brick-dust alone. On some occasions, in which a very tough cement is requisite, that will not crack though exposed to repeated blows, as in fastening to a block metallic articles that are to be cut with a hammer and punch, A strong cement, insoluble in water, may be made from cheese. The cheese should be that of skimmed milk, cut into slices, throwing away the rind, and boiled till it becomes a strong glue, which however does not dissolve in the water. This water being poured off, it is to be washed in cold water, and then kneaded in warm water. This process is to be repeated several times. The glue is then to be put warm on a levigating stone, and kneaded with quick lime. This cement may be used cold, but it is better to 88 Cement-Porcelain-Dry-Rot in Timber. workmen usually mix some tow with the cement, the fibres of which hold its parts together. Porcelain. VOL. I. Dry-Rot in Timber. GENTLEMEN:-The following observations on the probable cause and prevention of the Dry-rot, may not be unworthy the notice of your intelligent readers, so as to induce them to point out what is erroneous. In order that general good may in time be THE most beautiful and the finest of all earthen wares is porcelain. The art of mak-produced on this interesting subject, every ing it is one of those in which Europe has been excelled by oriental nations. The first porcelain that was seen in Europe, was brought from Japan and China. The whiteness, transparency, fineness, neatness, elegance, and even magnificence of this pottery, which soon became the ornament of sumptuous tables, did not fail to excite the admiration and industry of Europeans. one should contribute his mite of information towards increasing and improving the general stock: in the multitude of council only is wisdom to be found. The dry-rot appears to arise from the aqueous matter in timber suffering decomposition, for the following reasons: there is no dryrot in wood kept perfectly deprived of humidity, and water does not produce it in wood which is always wet throughout; but humidity is indispensable to produce this rot; yet the wood, when rotted, has not the slightest appearance of humidity, it being pulverent and dry as possible. Father Entrecolles, missionary at China, sent home a summary description of the process by which the inhabitants of that country make their porcelain, and also a small quantity of the materials which they employ in its composition. He said that the Chinese Evaporation might remove the water, but composed their porcelain of two ingredients, would not produce dry-rot, neither would one of which is a hard stone or rock, called by dryness. The hamid state of the wood them petuntse, which they carefully grind to when sound, and its desiccated state when a very fine powder, and the other, called by rotted, leaves a fair inference that the drythem kaolin, is a white earthy substance, rot is the natural consequence of the internal which they mix intimately with the groundwaters or juices in timber having suffered depetuntse. Reaumur examined both these composition. matters, and having exposed them separately to a violent fire, he discovered that the petuntse had fused without addition, and that the kaolin had given no sign of fusibility, He afterwards mixed these matters, and formed cakes of them, which, by baking, were converted into porcelain similar to that of China. Perfect dryness, and wetness even to saturation, it is well known prevent dry-rot; but the former state being impossible to be maintained in ships, the latter affords ample means for conveying the anticeptic principle to all parts where the cause of the evil ex|ists; and if so, the succulent wood is the most capable of preservation by art, the remedy being to diffuse throughout the aqueous matter in the wood that which shall keep it in a compound state, as a fluid, or cause it in this mixed state, by being, as it were, a new substance, to become aggre Reaumur gave the quality of porcelain to glass; that is, he rendered glass of a milky color, semi-transparent, so hard as to strike fire with steel, infusible, and of a fibrous grain, by means of cementation. The process which he pursued is not difficult. Com-gated with the wood itself. mon glass, such as that of which wine bottles are made, succeeds best. The glass vessel, which is to be converted into porcelain, is to be enclosed in a baked earthen case or segger. The vessel and case are to be filled with a cement composed of equal parts of sand and powdered gypsum or plaster, and the whole is to be put into a potter's kiln, and to remain there during the baking of common earthenware; after which the glass vessel will be found transformed into such a matter as has been described. Why do you desire riches and grandeur? Because you think they will bring happiness with them. The very thing you want is now in your power-you have only to study contentment. It should be noticed, likewise, that as no species of matter can act on itself, neither does any phenomenon taken place without many proximate causes being concerned; and hence the aeriform medium which surrounds timber subject to the dry-rot, is one in promoting dry-rot circulation, as much as galvanic circulation, when more or less promoted by confined or unventiliated air, contributes to that transfer of elementary matter from sound wood, which leaves nothing but decomposed wood behind. Pure air has no such disposition, but even in pure air, woods in contact, from their dissimilarity and internal humidity, galvanise each other. Humid wood may be considered as containing water in every physical point, the elements of which, when it is decomposed, become mixed with certain constituent elements of the No. 6 Dry-Rot in Timber-Gold and Silver. wood, that assisted the decomposition; and the whole become evolved together, vitiating the air they enter, and leaving the wood throughout like a tissue deprived of its warp or weft, destroyed in stength and texture, and greatly reduced in weight. Gold and Silver. 89 Prideaux says, that gold and silver were much more plentiful in the time of David and Solomon, and for 1,500 years afterwards, than they are present; and that the mines of Arabia being exhausted, and the goid and silver with which the world abounded being wasted by the barbarians, the mines of Mexico, Peru, and Brazil, have not been able to repair the loss. He mentions two or three instances of the vast riches of private men in ancient times. Pythias, the Lydian, possessed gold and silver to the amount of near There is nothing more silly than to imagine that fungus (which but occasionally appears,) is the cause of dry-rot, it being but the consequence of some part of the juices of the wood or tree (that in its growing state would have eventually become wood,) vegetating in a novel direction: many are the instances of fungi without dry-rot, and dry-ly five millions sterling. Marcus Crassus, rot without fungi being any way present. The foregoing may be considered approximations to the cause and progress of wood suffering the dry-rot, which, if even bordering on the fact, will, in efficient hands, be doubtless productive of a preventive to this great national evil. The discovery of the cause should, in this enlightened age, most indubitably be attended with its concomi tant cure. Experience proves how almost imperishable timber is rendered by having been buried for a length of time in the earth; would not trees newly felled, by such a process, have their original organization so destroyed, and their juices changed, as to render them as inactive on each other as water on marble, or marble on water? Similar is the process of preserving meat; the lobes are broken by rubbing, in order that salt shall mix with their aqueous contents, and prevent decomposition, as the same is effected without salt, if the animal matter be deprived of all humidity. Again, would not the water in which thick stuff is boiled, if saturated by unslacked lime, by its deposit on entering the wood, prevent decomposition of its internal water? All wood imbedded in mortar, is preserved by it from dry-rot. There is nothing cheaper for the purpose. Obtained pellucid, no inconvenience would arise in working the wood after being boiled, and the residual lime would still have its use. Soaking in lime-water might also be resorted to. To conclude as I commenced, I flatter myself these speculations may be improved on for the benefit of society, and which, through the medium of your very valuble Magazine, are certain of being noticed by every inquirer after scientific information. Your obedient servant, T. H. PASLEY. If you have a family, it is no more allowable that you squander away your substance than for a steward to embezzle the estate of which he is a manager. the Roman, after feasting all the people of Rome at 10,000 tables, and giving every citizen corn enough to last him three months, found the remainder of his estate to be equal to about 1,400,000. Lucullus, a Roman senator, used to expend 50,000 denarii (1,4007.) every time he supped in his hall Apollo, and this was as often as any of the better sort supped with him. It has been computed that Nebuchadnezzar's golden image, and the various other images, utensils, &c. of gold, in the temple of Belus, at Babylon, amounted in value to about 34,000,000l. Vast loads of gold and silver were often carried in triumph before Roman generals, when they returned from conquered provinces. The gold with which Solomon overlaid the most holy place only, a room thirty feet square, amounted to more than 38,000,000l. Crito, a writer in the Christian Spectator, supposes also, that the amount of wealth was formerly much greater than at present. He notices the following instances:-the Israelites, soon after their escape from Egyptian bondage, offered for the tabernacle gold and silver to the amount of 170,000,000l. (Exod. xxxviii. 24, 25.) This was probably borrowed of the Egyptians; but it shows that gold and silver were plenty in Egypt. The contributions of the people for the sanctuary, in the time of David, exceeded 6,800,000l. (1 Chron. xxix. 7.) The sum which Haman offered Ahasuerus, on condition of being permitted to order the destruction of the Jews, was 10,000 talents of silver, or 340,000l. (Esther iii. 9.) The immense treasure David is said to have collected for the sanctuary (1 Chron. xxii. 14,) amounted to 889,000,000 of pounds sterling (Crito says 798,000,000, but erroneously,) a sum greater than the British national debt, and exceeding all the money coined since the discovery of America. It is supposed by some learned men, that David never amassed such an immense sum, and an error has been made by the transcribers of this book. Prideaux conjectures that the talents of gold and silver given by Daivd and others for the temple, might be of ano-||matic; whereas a chemical manufacture dether sort, of far less value than the Mosaic pends on the play of delicate affinities betalents. He remarks that if these talents tween two or more substances, which it has are valued by the Mosaic talents, they would to subject to heat and mixture under circumhave built the whole temple of solid silver. stances somewhat uncertain, and must thereCrito estimates the talent of silver at 342 fore remain, to a corresponding extent, a pounds sterling, and the talent of gold at manual operation. The best example of 5,475 pounds sterling, according to Dr. Ar- pure chemistry on self-acting principles buthnot's "Tables of Ancient Coins, &c." which I have seen, was in a manufacture of inserted in the translation of Jahn's Archæ-sulphuric acid, where the sulphur being ology. kindled and properly set in train with the The following is the estimated produce of nitre, atmospheric air, and water, carried on the different gold and silver mines in modern the process through a labyrinth of comparttimes-Of gold, the mines of Europe pro- ments, and supplied the requisite heat of duce, in sterling, only 185,0207. Northern concentration, till it brought forth a finished Asia, 76,7701. Amercia the rest of the total commercial product. The finest model of of 2,467,260ễ., in the following proportions : an automatic manufacture of mixed chemis-New Spain, 229,6301.; New Grenada, 672,- try is the five-colored calico machine, which 500l.; Peru, 111,530/.; Potosi and provinces continuously, and spontaneously, so to speak, east of Buenos Ayres, 73,180/.; Chili, 400,|| prints beautiful webs of cloth with admira5501., and Brazil 980,8701. Of silver, the ble precision and speed. It is in a cotton total amount of which is 7,314,6704., Europe mill, however, that the perfection of autoproduces 484,580l. and Northern Asia, 199,- || matic industry is to be seen; it is there that 6301. America furnishes the rest. New the elemental powers have been made to Spain, 4,945,340.; Peru, 1,292,4407.; Poto-animate millions of complex organs, infussi, &c. 1,019,070l. and Chili, 62,8207. ing into forms of wood, iron, and brass an intelligent agency. And as the philosophy of the fine arts, poetry, painting, and music may be best studied in their individual master-pieces, so may the philosophy of manufactures in this its noblest creation. The following extract from Ure's Philosophy of Manufactures, (a work but little known in this country,) will be found to contain much useful knowledge for the practical and theoretical mechanic. There are four distinct classes of textile General view of Manufacturing Industry.fibres, cotton, wool, flax, and silk, which constitute the subjects of four, or, more cor NO. I. the woollen; third, the worsted; fourth, the flax, hempen, or linen; and fifth, the silk. These five factories have each peculiarities proceeding from the peculiarities of its raw material and of its fabrics; but they all possess certain family features, for they all employ torsion to convert the loose slender fibres of vegetable or animal origin into firm coherent threads, and, with the exception of silk, they all employ, extension also to attenuate and equalize these threads, technically styled yarn. Even one kind of silk which occurs in entangled tufts, called floss, is spun like cotton, by the simultaneous action of stretching and twisting. Manufacture is a word, which, in the rectly speaking, five distinct classes of facvicissitude of language, has come to sig-tories; first, the cotton factories; second, nify the reverse of its intrinsic meaning, for it now denotes every extensive product of art, which is made by machinery, with little or no aid of the human hand; so that the most perfect manufacture is that which dispenses entirely with manual labor. The philosophy of manufactures is therefore an exposition of the general principles, on which productive industry should be conducted by self-acting machines. The end of a manufacture is to modify the texture, form, or composition of natural objects by mechanical or chemical forces, acting either separately, combined, or in succession.Hence the automatic arts subservient to general commerce may be distinguished into Mechanical and Chemical, according as they modify the external form or the internal constitution of their subject matter. An indefinite variety of objects may be subjected to each system of action, but they may be all conveniently classified into animal, vegetable, and mineral. The above-named five orders of factories are, throughout this kingdom, set in motion by steam-engines or water-wheels; they all give employment to multitudes of children or adolescents; and they have therefore been subjected to certain legislative provi||sions, defined in the Factories Regulation Act, passed by Parliament on the 29th August, 1833. A mechanical manufacture being commonly occupied with one substance, which It is probable that 614,200 work-people it conducts through metamorphoses in regu- are constantly engaged within the factories lar succession, may be made nearly auto-of the United Kingdom: of which number No. 6 General View of Manufacturing Industry. 91 561,900 belong to England and Wales; we shall then be led to conclude that at 46,825 to Scotland; and 5,475 to Ireland.* least double the amount of personal indus-, Fully five-tenths of them are under twenty-try is engaged in the arts, manufactures, one years of age, and three-tenths of these young persons are females. It must be remembered, however, that besides these 614,200 inmates of factories, a vast population derives a livelihood from the manufactures of cotton, wool, flax, and silk, such as the hand-weavers, the calico-printers and || dyers, the frame-work knitters, the lacemakers, lace-runners, muslin-sewers, &c. &c. It appears from the Parliamentary Returns of 1831, that in Great Britain, out of a total population of 16,539,318 persons,|| there are of Agricultural Laborers and Laboring Occupiers, Manufacturing Labor ers, and trade, to what is engaged in agriculture. Considerably upwards of one-tenth of the population of this island is actually employed in manufactures; and probably little more than one-fifteenth in agriculture. This conclusion ought to lead our legisla tive landlords to treat the manufacturing interests with greater respect than they have usually been accustomed to do. If we consider, moreover, how much greater a mass of productive industry a male adult is equivalent to, in power-driven manufactures, than in agriculture, the balance in favor of the former will be greatly enhanced. France, which has for upwards of a century and a half tried every scheme of public 1, 055,982, and of premium to become a great manufacturing country, has a much less proportion than one employed in trade for two employed in agriculture. M. Charles Dupin, indeed, 404,317 Whence there are 1000 agricultural to 383 has been led by his researches into the com strictly manufacturing laborers Persons employed in retail trade, or in handicraft, as mas parative industry of France and of the United Kingdom, to conclude that the agricultural produce of our country amounted in value to 240 millions sterling, and that of his own to 180 millions sterling, being the ratio of three to two; and that our manufacturing power is inferior to that of France in the proportion of sixty-three to seventy-two; or as seven to eight. There can be now doubt that his agricultural estimate underrates France, as much as his manufacturing estimate underrates Great Britain. This Island is pre-eminent among civilized nations for the prodigious developement of its factory wealth, and has been therefore long viewed with a jealous admiration by foreign powers. This very pre-eminence, however, has been contemplated in a very different light by many influential members of our own community, and has been even denounced by them as the certain origin of innumerable evils to the people, and of revolutionary convulsions to the state. If the affairs of the kingdom be wisely administered, I believe such allegations and fears will prove to be groundless, and to proceed more from the envy of one ancient and powerful order of the commonwealth, towards another suddenly grown into political importance, than from the nature of things. In the recent discussions concerning our factories, no circumstance is so deserving of remark, as the gross ignorance evinced by our leading legislators and economists, gentlemen well informed in other respects, relative to the nature of those stupendous manufactures which have so long provided the rulers of the kingdom with the resources of war, and a great body of the people with |