Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/281

 Manon 29, 1872. THE BUILDING NEWS. lupe 263 get the better for the purpose, but always with ex- planatory geometrical elevations. Mr, Sharpe con- tinued to say that there was another great objec- tion to presenting a building solely in elevation. He defied any one, even an architect, to say what the effect of certain projections would be. He directed attention to four drawings on the wall, re- presenting two well-known towers and spires, and illustrating what was a very common thing in prac- tice—the structure of an octagon upon a square. Mr. Sharpe continued: We know very well that every octagon put upon a square in geometrical ele- vation presents the same breadth from top to bottom. The moment you have it in perspective, you see that the octagon is less than the square, except from certain points of view ; from the four cardinal points of view, if you will permit me to call them so, perhaps you get avery good geometrical elevation, but from any other point of view, you do not see that effect. The mode in which the building ought tobe presented to view is not an exceptional one, but the ordinary one; that which is usually seen. The manner in which thelaws of perspective affect the appearance of octagonal spires and square towers is well illustrated in the four drawings of the towers and spires of Ewerby and Threckingham Churches, of which the left-hand drawing in each case re- presents the geometrical elevation, and the right- hand drawing the perspective view. The contrast is startling; the clumsy predominance of the spire over the tower in the left-hand drawing in both cases is as remarkable as the graceful effect of perspective upon both structures in the right-hand drawings. Now, will you tellme that the architect designed the left-hand drawing first, and let the right-hand one come out asit might? No, he knew very well, perhaps from previous experiment, what would be the perspective effect of the building he intended to present to the public. That is the mode in which all architects who profess to be artists ought to study and produce their designs and present them to the public. Permit me to draw your attention to another fact, and a very important one. Suppose for example, the elevation of the west front of Wells Cathedral and all the statues it contains were to be drawn as they really are; or, taking a modern case, that the sculptor of any of our public monu- ments—that of Nelson, for instance—were to design and present ts the public his drawing in geometrical elevation instead of in perspective; why, such a drawing would be totally repugnant to the ideas of everybody who saw it, because it would present the lower part of the figure out of proportion to the rest; in fact, it would not be foreshortened, as it would in perspective. I think that we may demand the same privileges as architects that sculptors have, and I think we ought to present our designs in the same way—viz., from a perspective point of view, and not in elevation, for the one presents distortion, and the other presents reality. One word more, as T should fall very short of what I mean without saying what I am going to say. I protest as emphatically as any gentleman here will against the dressing-up of perspective views by means of colour, by means of accessories of all kinds that do not form any portion of the architecture of the building. I protest as emphatically as any one can protest against that sort of meretricious and adventitious aid to perspective views, and can only express the hope that the Institute may come to the decision that all drawings sent inin competitions should be devoid of all adventitious ornaments of any kind whatever except that derived from the introduction of the human figure, drawn in true proportions, and that all such drawings should be tinted in one colour only. ' —_—_<—___ VENTILATION AND PURIFICATION IN FACTORIES, &c.* aot previous to the late war, M. Charles de Frécinet, mining engineer, was charged by the late Imperial Government with a commission to visit the most important factories and workshops in England, France, Germany, and Belgium, and to report on the means adopted to prevent the ill effects of the various deleterious agencies on the health of the operatives. The results of this investigation were printed in four large volumes, but the very voluminous nature of the work, and the stirring events that followed upon its appearance, have caused it to be but little noticed, except by a few scientific men. It will, therefore, be useful to note a few of the observations of M. de Frécinet, and especially of those which refer to foreign countries, After speaking of the good effects produced in Durham by the construction of tall chimney-shafts for the coke ovens, M. de Frécinet says that in Bel- ginm all the new coke furnaces are compelled by law a en ESS eae ee Ye to have chimney-shafts of 45ft. to 60ft. high, in order to ensure the carrying off of the gases. In the wine-making districts of France, it has been found that exhalations from the lime and brick kilns have a most serious effect on the quality of the grapes; the wine extracted from them has an unpleasant taste of soot, and the proprietors of the kilns have often been compelled to pay heavy damages to the wine- growers. The construction of tall chimney-shafts, therefore, became an absolute necessity, and the case of §, Etienne is cited as one in which the mischief caused by the numerous coke furnaces around the town was completely stopped by the adoption of tall shafts. Ventilation by means of fans placed in the build- ings themselves, or applied directly to the engines, is pretty generally adopted in the French white-lead, tobacco, and leather-dressing manufactories, and in woollen and cotton mills. In other cases, water is used to condense injurious vapours; and in the soda works high stone towers are employed to condense the smoke. The dangers which those workmen run who have habitually to make use of quicksilver are too well- known to require description. In the works at S. Gobain, Cirey, and Chauny, the men are not em- ployed more than three days in the week in the silvering of looking-glass, and the windows, which are provided with good ventilators, are kept open whenever possible. The tools, covered with flannel, by means of which the mercury is spread on the tin- foil, have handles 4ft. long; the mercury is kept in hermetically-sealed receptacles, and the cloths through which it is passed, in order to remove impurities, are beaten in well-closed boxes and in the open air. In silvering by means of mereury, by the method of MM. Bonin, of Paris, an admirable method is adopted to get rid of the fumes. Over the fire by which the mercury is driven off in the form of vapour is anopen chimney, covered at the top with a large glass globe, and the workmen are protected by a shield, through which they pass their arms. Some manufactures have not been much benefited by science; for instance, no means have been found of reducing the unhealthiness of the chromate of potash works. At those of M. Clouet, of Havre, most of the workmen are subject to cancer, which attacks the nostrils, and which is produced by the particles of chromate which float in the air. The production of sulphate of quinine is no less danger- ous; it affects in a singular manner those who have to manipulate it. The operation of millstone cutting is extremely unhealthy. The population of La Fertésous-Jouarre, the chief centre of this important trade, is decimated by the introduction into the lungs of the silicious particles which are in suspension in the air, and it is calculated that ten years’ employ- ment in the business generally produces fatal disease. The charcoal dust used in the iron and bronze foundries for covering the moulds is also found very injurious to the health of the men engaged, and in consequence potato flour is now generally used in Paris, in place of charcoal, with good results. In bark grinding and other works, where simple ventilators have generally been used, reservoirs are now added, so that the dust is both withdrawn and collected, and does not contaminate the air. In the cotton mills of M. Fauquet, at Oisel, the principal room, which is nearly 3,000 feet long, and is used both for carding and spinning, is constructed in a special manner, with the triple object of secur- ing uniform temperature, driving out the impure air, and supplying fresh air. In order to prevent the variations of temperature arising from change of weather, the vaulting of the roof was covered with honeycombed work, in the following manner :—A number of glass bottles were arranged upright and in alternating rows, mortar was then poured into the interstices, and, the bottles being removed, left a spongy, porous coating, which was afterwards covered on the top with plaster. By this means a double ceiling was produced, enclosing a stratum of warm air contained in a multitude of cells. Two powerful ventilators in a subterranean gallery carry off the impure air and supply fresh, the circulation of the latter being secured by passages beneath the flooring, having thirty openings into the room. Lastly, a jet of water is used in the fresh-air gallery when additional humidity is requisite. In the tobacco factories, uniformity of temperature is not requisite, and the dust is much less than in cotton and other mills, but there are exhalations from the fermenting tobacco to be removed. In the French Government factories, ventilating fans are used, and eight cubic metres of air per hour are allowed for each workman. The factories are heated with caloriféres, with tall chimney shafts. In some white-lead works, and where lead enamel for telegraphic insulators is ground, the millstones are tion with the ventilating fan. In M. Kestner’s fac- tory at Thann, the rooms in which chlorate of lime is made have leaden pipes, which carry off the gases to the main chimney-shaft; a register is opened an hour or two before the men arrive to their work, a strong current is established, and the air of the place completely renewed. Tn the lead foundry of M. Lepau, at Lille, each furnace has a eupola which communicates by means of a flue furnished with a register, with the bottom of the cinder-hole of the steam-engines. Similar arrangements are adopted in nearly all the French factories employing mineral oils and greases, and where pyroligneous acid and sulphuretted hy- drogen are produced. The method is considered applicable to all works where organic substances are treated; and the economy of combustibles is consider- able. In some soap works, the boilers are furnished with iron hoods, which have pipes which conyey the gases beneath the steam-engine furnace, where they are dispelled by a jet of steam. At Aix-la-Chapelle, the Prussian authorities have strictly prohibited the grinding of needles, except in shops provided with thorough means of ventilation and for carrying off the atomsof metal. In some of the shops at that place, each stone is furnished with its own ventilator. In the chemical works of M. Mercks, at Darmstadt, where great quantities of belladonna are prepared, a large hood connected with a chimney is brought down over the grinding- mill, and never allowed to be raised until the grinding is done and all the dust carried off. In many other drug works the grinding mills are en- closed and ventilated in like manner. In the chemical works of M. Gundelach, at Mann- heim, the men who repair the leaden chambers for the manufacture of sulphuric acid and chioride of lime wear a head-piece, connected by flexible tubes with an air-pump, asin diving. The same plan is adopted at Worms and at Heilbronn. The severity of the Belgian Government in such matters has caused the manufacturers to adopt many ingenious devices. In M. De Hemptine’s works, at Molenbeck, S.-Jean, near Brussels, the platinum still for the concentration of sulphuric acid is built into a wall; over the still is a cover, in the centre of which is the man-hole, which, when the mill is at work, is closed hermetically by a leaden plate, and from the space thus formed between this cover and the top of the still a leaden pipe carries off the vapours into the main chimney-shaft of the works. In the extensive paper-mills of M. Godin, at Huy, where chlorine gas is used for bleaching the pulp, the gas is carried off by means of stone channels, which are in communication with a central chamber 30ft. high, where absorption is effected on a grand seale. At Ghent and Dusseldorf, white-lead is groundin oil or water, in order to prevent the dispersion of the fine particles. This substance used to be em- ployed in bleaching lace, but it caused such mortality amongst the workmen that the Government inter- dicted it. In the chemical works of M. Zimmer, at Sachenhausen, near Frankfort, the bark for the pre- paration of sulphate of quinine is ground in a state of fermentation in mills hermetically sealed. In the purification of the sulphate, the evaporating vats are placed in a special room, and under domes furnished with special shafts. At the lucifer-match works of M. De Roubaix, at Heurixen, near Antwerp, the five buildings in which the various preparations are made are venti- lated by means of a great central chimney-shaft, which receives the gases from the steam furnaces, and the draught of which is aided, when necessary, by a special furnace. A spacious subterranean channel runs round the base of each building, and terminates in the central shaft. An opening is made in every part where phosphorus is employed, with a channel leading to the main one above de- scribed. At the woollen works of MM. Hauzein, Gérard, & Co., of Verviers, the carding machines are situ- ated in a separate building, provided with ventilating fans. The wool is placed on a rack, forming one side of an otherwise closed case; a powerful fan acts within this enclosure, while a current of hot air is directed against the walls of the building. By these simple means, the workpeople are relieved from all the dust and other matters which would contaminate the air. At Ypres, the lime used in the purification of gas, upon being withdrawn from the purifiers, is imme- diately mixed with cinders, which destroy the un- healthy odours, and the mixture is eventually sold as manure. After the previous accounts from other countries of the aid rendered by science to humanity, it is hard to haye to transcribe the following expressions
 * From The Society of Arts Journal.
 * enclosed in tight cases, and arein direct communica-