1841.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



iiS 



tlie arm as the shocks of a small Leyden phial, producing a good deal of 

 merriment to the astonished workmen who were present, to see tire and feel 

 the shocks from steam, an article they all supposed themselves perfectly fami- 

 liar with. 



In the evening the experiment was resumed, to see the ctTects in the dark, 

 when they proved the experimenter to he highly charged with electricity. 

 The board on which he stood, not bejng rounded, each corner had a brush of 

 light two or three inches long, like as many tassels, while every point of his 

 dress and hair became highly luminous upon the persons standing near him. 

 On this trial, sparks were drawn fully two inches long, which required some 

 little courage to engage with, from their shocking propensities. 



The experiments were made upon the steam of two boilers, thirty-two feet 

 long by six diameter, first with steam equal to 12 ft. upon the inch, and lat- 

 terly at 25 ft. — the increase of pressure adding to the effect. However, the 

 experiment was perfectly and satisfactorily performed with the siu-plus steam 

 issuing from the safety-valve while the engine was going upon trial. Mr. 

 Condie is of opinion that, from such boilers, with a properly constructed 

 prime conductor, of large surface, sjjarks may be drawn from six to eight 

 inches long, and large jars charged in a few seconds. The wonder w.as that 

 the experiment succeeded at all, as the apparatus was altogether rude. The 

 floor where the temporary stool stood was covered mth dust, shavings, &c., 

 which acted as conductors in stealing away the electricity from the experi- 

 menter. — Ayr Observer. 



PUBLIC WORKS IN PARIS. 



The Afoniteur takes a survey of the principal public buildings in Paris and 

 its immediate vicinity, either terminated during the past year, or the works 

 of which have been much advanced. We gather from it the following parti- 

 culars I — It appeal's that the interior of tlie new buildings added to the Lux- 

 emburg would have been entirely finished hut for the interruptions caused 

 by the political trials that have taken place before the Court of Peers. Seve- 

 ral alterations have been made in the gardens, and the whole may now be 

 expected to be speedily terminated. Statues or other decorative objects are 

 to be placed on the pedestals of the Pont de la Concorde, to make it har- 

 monize with the present highly decorated aspect of the Place de la Concorde. 

 Nothing but works of ornamentation now remain to be done at the Made- 

 leine. The paintings by Messrs. Abel de Pujol, Schnetz, and Signol have 

 been uncovered in the interior, and the statues that are intended for the 

 several altars are far advanced. The Abbey of St. Denis will still take two 

 years before all the repairs are completely terminated. During the last year 

 the great circular window in the uorth transept, and the organ-loft, have been 

 finished. The works in the Palace on the Quai d'Orsay are not yet termi- 

 nated, but the Court of Accounts is expected to move into that building dur- 

 ing the spring. The works for new bureaux at the office of the Minister of 

 the Interior, Rue de Crenelle, are rapidly advancing : as are also those at the 

 hotel of the Minister of Public Works, Rue St. Dominique. The archives of 

 the law department are to be removed from the Salute ChapeUe to the new 

 buildings at the Hotel de Soubise, Rue du Chaume, prejiaratory to the re- 

 storation of the former edifice. .\n amphitheatre for lectures has been erected 

 at the Observatory, and several buildings liave been made at the Veterinary 

 School of Alfort, for gi^ng better accommodation to the professors for their 

 lecture, &c. The buildings of the new Blind Hospital, Boulevard des Inva- 

 lides. will shortly be entirely roofed in ; and the additional erections at the 

 Lunatic Asylum at Charenton are going on rapidly. Numerous public budd- 

 ings, such as the Bibliotheque Royale, the Bibliotheque St. Genevieve, and 

 the Conservatoire des Arts et Metiers, are in such a dilapidated state, that 

 the Chambers will no doubt vote the funds requisite for repairing them, or 

 erecting new ones. 



NEW INVENTIONS AND IMPROVEMENTS. 



PAPYROGRAPHY. 



This is a new invention for reproducing drawings, manuscripts, and all kinds 

 of designs to an unlimited extent, and by means much cheaper than at pre- 

 sent known. This process, which is called by M. de Manne, the inventor, 

 Papyrograjjhy, is very fully noticed in a late number of the Monitevr, 

 from which we abridge the following particulars. — The mode by which M. de 

 Manne produces designs, &c., on paper, is thus described. After having, by 

 means of his prepared metallic ink, traced the drawing on common writing 

 paper, he contrives, by an operation which he at present keeps secret, to 

 make the lines rise from the paper in relief, and become extremely hard and 

 durable. He fixes this matrix on a plate of metal, on which he then places 

 the paper that is to receive the impression. Over the paper he places apiece 

 of silk, and passes it under the roller of a copper-plate press ; when the 

 characters and lines on the manuscript or drawing are reproduced, stamped 

 in on the paper. These designs thus fixed on the plates are hard enough to 

 allow of a greater number of imprissions being taken without injury to them. 

 The part of the invention, which consists in obtaining plates of metal cast 

 from the matrix afforded by the drawing on the paper, is considered by the 

 committee of the Society of Arts of Mulhausen, who were appointed to ex- 

 amine it, as of still greater importance than any other. By this engraving 



on paper, say the committee, may be obtained impressions fully equal to what 

 can be had from wood engravings ; by this means, therefore, v.orks which 

 require illustrations may ):c ;.rintrd with great cheapness. In cngravisgs on 

 wood, the design and the subsequent cutting are necessary, b^it by the papy- 

 rographic method, the design is the only expense ; and it will jiroduce with- 

 out end as many engraved plates and impressions .is may be recpiired, at a cost 

 one half of tliat of the ordinary process ; and with a precision equal to that 

 of the original drawing. — As M. de Manne conducted his experiments at 

 Rouen, where there was no skilful metal founders, he hdjoured under great 

 disadvantage in his attem]>ts to bring his invention to perfection, but the spe- 

 cimens he sent to the committee were sutticient to convince them that his 

 ])lan was cap.able of answering all that be stated. Some of the specimens sent 

 to the committee presented the designs, and the printed copies from them in 

 relief to the height of from two to three millimetres, obtained solely from the 

 matrix traced on paper. The committee propose to extend the invention to 

 the printing of woven fabrics and |iaper. M. de Manne sent some plates pre- 

 pared for this object, but owing to the disadvantages under which he laboured, 

 the plates were not so perfectly cast as they ought to have been, to produce 

 the desired effect. The defect, ho\vever, he ascribes entirely to the unskilful 

 manner in which the Rouen founders took the cast of his matrices; for not 

 venturing to trust them with the paper moulds, he took easts of them in 

 plaster ; from which the metal plates were afterwards cast. It is to this cir- 

 cumstance that M. de Manne attril)utes the failure of his experiment, as it 

 was difficidt to take the cast in plaster from the paper so as to preserve the 

 sharpness of the outline. He says he is certain of the success of his process 

 as applied to the printing of papers and calicoes, but want of means with 

 him, as with many other inventors, prevents him from taking out patents, or 

 from carrying the invention into operation. The committee report that it 

 seems to them highly probable that if the inventor was placed in more fa- 

 vourable circumstances, be would arrive at remarkable and very useful results. 

 In conclusion they recommend the society to grant him a silver medal, though 

 the invention is not of a nature within their usual subjects for prizes. — /»i- 

 vciitors^ Advocate. 



BRICKS AND TILES MADE BY MACHINERY. 



The French Academy of Sciences lately appointed a committee to examine 

 a machine for making bricks, invented by M. Carville. The following is the 

 substance of their report. — The committee proceeded to examine the action of 

 the machinery in reference to its three principal functions, — of mixing the 

 materials, of moulding the bricks, and afterwards of extracting them from the 

 moulds. The mixing of the clay is performed in a vertical cyUnder, by means 

 of an iron axle, to which arms are fixed at different heights, which are fur- 

 nished with knives. A rotary motion is given to the axle, by the power of a 

 horse, applied to the end ot a long lever. The materials are thrown in at 

 the ujjper end of the cylinder, and when properly mixed, are passed into the 

 moulds, through au opening in the side towards the bottom. Inclined boards, 

 in the form of the sails of a wind-mill, are connected at the lower end of the 

 vertical axle. The pressure resulting from the inclination of these boards 

 constantly pressing against the clay during their rotatory motion, forces it 

 out of the opening ; a small vane, formed of iron plates, regulates and restricts 

 the manner in which it issues out. An endless chain, com])osed of moulds 

 of cast iron, joined to each other by hinges, passes under the base of the cy- 

 linder, and the moulds are thus filled with the prepared clay. A heavy roller, 

 of cast iron, begins the compression ; it is finished by drawing the loaded 

 moulds through a compressor, composed of two plates of iron, the surfaces of 

 which are not quite parallel. The removal of the bricks from the moulds 

 takes place immediately after the compression, by means of a rammer acting 

 from above. By causing the rammer, during the process, to move in the 

 same direction as the chain of moulds, a continuous action is obtained, by 

 means of very simple mechanism. The moment when the blow of the ram- 

 mer should be given is very ingeniously determined, by joints fastened to the 

 moulds. This motion, thus derived from the chain of moulds, and acting in- 

 variably with it, prevents the inconveniences that would result from the 

 lengthening of the chain, by the inevitable wearing out of the hinges. The 

 adhesion of the earth to the sides of the moulds, is avoided by their being 

 immersed, for half a revolution of the cylinder, in water, with which a vessel 

 placed under the machine is filled. — Two hoppers are introduced in the ma- 

 chinery, before and after the reservoir, where the earth is prepared. They 

 spread in the requisite quantities the fine sand with which they are constantly 

 supplied.. One of them spreads the sand before the moulds are filled, upon 

 plates of iron, connected together so as to form an endless chain, which serves 

 as the bottoms for the moulds. The other hopper sprinkles the surface of the 

 bricks before compression. Thus any adhesion of the substance continues to 

 be avoided both with the roller with which the compression begins, with the 

 iron work which completes it, and with the rammer which removes the clay 

 from the mould. For greater precaution, and in order to obtain more regular 

 surfaces, a slight stream of water continually moistens the pressing roller. 

 The bricks are received on an endless chain of iron plates, after they are taken 

 from the mould, by which they are conveyed to the kiln. The power of a 

 single horse, by turning a wheel, prepares and moulds about 1,500 bricks in 

 an hour. — The commissioners, on concluding their report, observed, that they' 

 had convinced themselves of the complete mixture of the substances forming 

 the bricks, by breaking and inspecting several of them. They inspected the 



