Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/300

 282 THE BUILDING NEWS. Arrm 5, 1872. flooring is laid not with plaster of Paris, but with mortar. Thus this thin arch is honeycombed, as it were, for lightness, and it is so strong that a room 25ft. square is quite safe for a dancing party. But it is important that you have good mortar for your walls, much lime, and little sand; the mortar should become as hard as the bricks. I have seen mortar in walls of six years’ standing, in Cincinnati, that I could dig out with my nails. This is not the wall for any kind of arch to rest on and against. Ob- serve that the curves of the little arches on top of the main arch run counter to the curve of the main arch. I still think that if several builders could club together, it would be well to send out here for a mason who fully understands the matter. I have been told that there are arches of this description at Volterra which have stood certainly several thousand years. They are in the tombs of that very ancient city, and the arch is called ‘ The Volterrano.’ I have seen these arches without any plaster on them, the bricks so laid as to present a beautiful mosaic ap- pearance. The cost of them is very small, as you must have perceived from the above description, and they are so light as to require no very great thick- ness of outer wall.” ——<—$_@o—__— REMOVING OLD PAINT. ESOLVENTS are not resorted to to any great extent by carriage-painters in the removal of old paint. Doubtless, the majority of painters have experimented with chemical mixtures claiming to be a great improvement over the old plan of soften- ing the paint by heat, but we think our experience will agree with others in this, that, while a chemical mixture may perform its work well and speedily, in so far as dissolving the paint is concerned, it also goes further and attacks the wood, leaving it in a furzy and gummy condition, on which it is difficult to get paint to dry firmly. House-painters use chemical burners to buta limited extent. Although their work is not required to be so perfect as that of the coach-maker, at least in Philadelphia such is the case. The charcoal furnace appears to be the favourite means with them of laying bare the wood, and when properly made it certainly performs its part well. The furnace is simple in construction, being nothing more than a small sheet-iron box with ahandle. One person can do the work, but generally two persons are employed, one to hold the furnace, and another, who is skilful with the chisel or knife, to remove the paint and regulate the distance to which the furnace shall be held from the paint, an important item, for when the body of old paint be- comes very hot it vitrifies, and when again it be- comes cold it clings with greater tenacity than before it was heated. The furnace would be the most economical device in a shop not supplied with gas. But shops lighted with gas can have nothing more economical, speedy, and free from deleterious effects than that of a gas-jet. All that is required are a few yards of rubber tubing, arranged to suit one of the gas pendants. The tube can be held in the left hand, and the knife or chisel in the right. The jet or flame is then made to strike the surface, and; when the paint is warmed through, the knife is used quickly in removing it. The gas-jet does not give out a great amount of heat, and therefore does not injure the joints of the body, or draw out the oil from the wood to an extent that delays the after painting. In removing paint, the heat should never be so intense as to quickly raise it up into blisters, itis only necessary to warm it through.—Coach- makers’ International Journal. SSS Ee BRONZE. N a paper lately read before the Paris Academy of Sciences, the author said that from all time it has been recognised that the oxidation of tin during fusion is destructive to the quality of bronze, but even up to the present time this has been op- posed by the stirring up of molten metal with wooden rabbles. The oxide of tin, which of itself has no strength, separates the molecules of the alloy, and reduces its power of resistance. The employ- ment of phosphorus as a reducer gives remarkably uniform results; the oxygen of the tin-oxide is ab- sorbed, and the resulting phosphoric acid goes to form phosphate of copper, which passes away in the seoria. Again, whilst ordinary bronze, submitted to the action of successively remelting, becomes more and more deprived of its tin, the phosphoric bronze can be cast over and over again without losing its proportion of tin. It appears to form itself as a fixed phosphate of tin, containing one equivalent of phosphate and nine of tin. By a series of pro- longed trials the properties which the phosphorus communicates to ordinary bronze have been ascer- tained. It appears the characteristics of the alloys change. The colour, when the proportion of phos- phorus exceeds } per cent., becomes warmer, and, like that of gold, largely mixed with copper. The grain or fracture approximates to that of steel. The elasticity is considerably increased; the absolute re- sistance under a fixed strain becomes in some cases more than double, whilst the density is equally in- creased, and to such a degree that some alloys are with difficulty touched by the file. The metal when east has great fluidity, and fills the moulds per- fectly, even to their smallest details. By varying the proportion of phosphorus, the particular cha- racteristic of the alloy which is most desired can be modified at will. An experiment was made in phos- phoric bronze with a 6-pounder gun, which was submitted to a destructive trial, in comparison with a similar piece in ordinary bronze, cast by the Royal Foundry at Liége. From the results of these trials, taken at various times during the firing, it appears that the durability of the gun of phosphoric bronze is very superior to that of the gun of ordi- nary bronze, and that with bursting charges which reduced the latter piece to fragments, the former could be still fired with perfect safety. The bronze employed had been obtained by the addition of phosphoric copper to metal provided out of the guns. The new bronze, prepared under suitable conditions of composition and melting, can be rolled out and hammered with the greatest ease, without losing its tensile strength. Cartridges that can be loaded and fired fifty times may be formed from it. The mechanism of breech-loaders has also been made from this material. Six thousand rifles fitted in this manner have been supplied to the Belgian Civic Guard. Of the same material also are cast toothed gearing for rolling-mills, hydraulic presses, bearers, eccentric straps, piston-rings, &e. It is also adapted to the production of works of art and decoration. The ease of casting, the good colour, and its resistance to oxidation, adapt it to these purposes. ——>—- THE DEMONS OF ART AND LITERATURE. R. MONCURE D. CONWAY delivered the last of his course of three lectures on Demono- logy, at the Royal Institution, on Saturday week. He commenced by alluding to the Greek Furies, de- scribed by Aischylus as the appointed scourgers of evil-doers, their name, Eumenides, signifying well- meaning, but who, in later times, were regarded as punishing from a divine necessity. Aftetwards Jupiter was invested with this power, but could only exercise it with the consent of the Dii Con- sentes and the Involuti. Under theologival transfor- mation, these gods became devils, and the Eumenides were called ‘“‘dogs,’ an ancient name. Then arose a new Pandemonium, correspending to the Pantheon, and the old combat between Light and Darkness, Ormuzd and Ahriman, reappeared as a raging struggle between Paganism and Christianity. In proof of this Mr, Conway referred to the beliefs of the early Fathers of the Church and to old frescoes, one of which, in the fourteenth century, represented devils bolstering up the statues of the gods and keeping them from falling off their pedestals. By degrees these grand statues were made ugly, and the beauty transferred to those of the Madonna and the saints, and eventually Art was turned against the shrines of Greece, which it originally built. Mazzini once said ‘All true art must either sum up and express the life of a closing epoch, or announce and proclaim the life of an epoch destined to succeed it.” But when Christianity came to Greece, Art had already summed up the past, and its very existence de- pended on the new order. By the necessity of the time, art was religious; there was no printing; and the symbols and the Scriptures could only reach the people as they were painted on the church walls. Hence proceeded the horrible faces given to the arch-fiend and his attendant imps, such as they appear in pictures of the temptation of S. Anthony and other saints, some of which verged upon cari- cature, showing the dawn of unbelief. Then arose the doctrine that the whole world belongs to Satan, and that he has the power of causing storms, diseases, and other calamities; and even Burton, in his ‘‘ Anatomy of Melancholy,” says that “the air is not so full of flies in summer as it is at all times of invisible devils.” To Satan, then, was consigned all that was gay and beautiful, with all learning, science and reason, and the divine kingdom was limited to those who abandoned the world altogether. The vastness of this concession, however, led to the idea of sorcery, which was in good part a revival of Paganism. Devils were said to be conjured up to bestow the wealth of which they were masters, for compacts such as those made by Faust with Mephistopheles ; and the performances of witchcraft assumed a religious form, and at the periodical witch-sabbaths mass was said to the Devil. The forms and characters of Pan, Mercury, Neptune, and the satyrs were gradually transferred to the Devil, followed by representations of him in the miracle-plays, and his ignominious treatment by the Vice, traces of which still appear in the pantaloon and clown of modern pantomines. The work of turning demons into mythological forms began with Dante, who passes through the Inferno hand-in-hand with Virgil; and by studying Dante, Swedenborg carried the Inferno into the mystical region of the North. He abolished demons, and turned them into labels for sins. Milton’s Pandemonium having been described, the lecturer concluded by a reference to the connection between psychological science and the problem of evil, and the opinions of Emerson and others on the subject. ——>—_—_ CLERKS’ BENEVOLENT INSTITUTION. ya fees annual meeting of this society was held on Wednesday week, at 165, Aldersgate-street, Mr. G. Plucknett, of the firm of Cubitt and Co., in the chair. Among those present were Messrs. Hannen (Holland & MHannen), Pritchard, Hall, Mullett (secretary), and others. The report stated that the society had now been established five years. There was a falling off in the donations this year, which was, however, partly counter-balanced by an increase in subscriptions, and a decrease in the tem- porary relief afforded to clerks in distress. The in- vested funds had reached £1,000. Two elections had been held, but they had only increased the number of their pensioners by two. The offices of the society had been removed to 27, Farringdon- street. The accounts showed receipts from life sub- scriptions of £177 14s. 24.; subscriptions to orphan fund, £49 12s. 3d.; and other items, making a total of £248 16s, The society had last year expended £88 6s. 8d. in pensions, and £5 in temporary relief. The report was adopted, and the following officers of the society elected :—President, Mr. G. Plucknett; treasurer, Mr. G. Prestige ; committee, Messrs. All- bright, Bayes, Brookes,. Foy, Hadland, Mason, Ward, and Carter ; auditors, Messrs. Attryde, Boutle, and Thacker. BUILDERS’ Cidil Cugineering. THE TUNNEL UNDER THE MERSEY, FPIHE tunnel which is to connect Birkenhead and Liverpool has been commenced. The trade in the Birkenhead Docks has been very much retarded for the last few years, and prevented from ever attaining its proper dimensions by the want of suffi- cient means for the transit of goods from Liverpool. The tunnel, according to the Birkenhead and Che- shire Advertiser, will be about three miles in length, about one-third of which will be under the bed of the river Mersey, and will connect nearly all the rail- ways in England with the Birkenhead Docks. The preliminary operations for the formation of the tunnel have been completed. A hoarding has been erected on the South Reserve land, between Shore- road and the river, close to Woodside Ferry, and on Monday a number of workmen commenced prelimi- nary operations for sinking a shaft in order to attain the depth of 70ft. below the bed of the river, at which point the cutting of the tunnel railway will be undertaken. The tunnelling will be performed with two machines, each of which will make a cutting 15ft. in diameter with a pressure of 30 horse-power engines. Two other shafts will be sunk on the Birkenhead side, one on the upper side of Shore- road, and the other between the gasworks and Green-lane, Tranmere, where will be situated what may be called the Cheshire terminus, the line there joining the Birkenhead and Cheshire railway, thus giving direct access from London into Liverpool, under the Mersey. As most of the materials dis- lodged in the cutting will be brought to bank at Birkenhead, it will be some time before the work commences on the Liverpool side, the only materials to be brought up there being those displaced in the downward shaft, which will have to be driven in order to reach the eastern end of the tunnel. This will be next the Harbour-master’s office. It is antici- pated that, unless serious geological “faults” are met with, the cutting of the tunnel, which is to ac- commodate a double line of rails, will be completed in two years. PIERS AND HARBOURS. Tue Board of Trade report that they are proceeding with several applications for provisiona] orders, to