Popular Science Monthly/Volume 42/December 1892/Recent Applications of Paper
By M. EMMANUEL RATOIN.
THE year 1891 was certainly one of those in which new industrial applications of paper were most numerous. The idea of using paper in place of stone in the construction of houses is already old; but paper to take the place of glass in windows, of clay in flower-pots, of iron in railway rails, wagon-wheels, and horseshoes, of porcelain in laboratory ware, of wood in barrels, it having already taken the place of that material in small boats, paper in pulleys, are applications as novel as bold. The manufacture of window-panes of paper was first tried in the United States. The panes have the appearance of milky glass, and the property of intercepting the light-rays while letting the heat-rays through, which makes them suitable for greenhouses. It is estimated that a paper window-pane ninety-four by sixty-three centimetres in dimensions in a wooden sash with iron appliances, will cost about eighty-five cents, and last on the average four years.
One of the most ingenious of the new applications of paper is in pulleys. These pulleys, the invention of M. Burot, have a center of cast iron and spokes of iron, bearing a bracing on which the paper felloe rests. This bracing supports the felloe during its manufacture, and thus gives it more firmness. The paper, of a special quality, is glued, rolled, and compressed upon the bracing in a single operation. The crown should then be dried and dipped in a mixture of linseed oil and resin. These pulleys, much lighter than those of iron, are also appreciably cheaper. They are used for the transmission of forces of from a half horse power to four horse powers.
Paper flower-pots have the advantage over earthen pots of being unbreakable and much lighter. If their net cost were considerably less than that of the earthen pots, they might replace them in the immense use made of them by gardeners and forest cultivators. They are imputrescible, impermeable, and shed the water. Like similar articles in terra cotta, they are adapted to ornamentation. Covered with a coat of enamel, or painted, they have the advantage over ornamental earthen pots of lending themselves more readily to the fanciful forms which manufacturers like to impose upon them.
M. A. Petit, engineer, has described to us the processes of manufacturing them thus: A paper pulp is taken composed of eighty-five parts of wood pulp and fifteen parts of rag pulp, and is shaped in molds to the desired form. The pneumatic or the centrifugal process of molding is used, according to circumstances, and does not differ essentially from those employed in porcelain factories. The articles are dried in air and then desiccated in a current of warm air; after which they are placed in an iron cylinder of one cubic metre capacity, which can be hermetically closed. A vacuum is formed in the cylinder in order to withdraw the air from the objects which are placed in it, and is maintained for four hours, after which a liquid composed of petroleum essence, colophony, linseed oil, and paraffin is admitted; this liquid being heated to a temperature of 75° C. before it is let into the cylinder. The articles are kept immersed in it for a quarter of an hour, when they are withdrawn and placed in a similar cylinder heated to 100° C, for the purpose of expelling the petroleum and recovering the solvent for use in other operations. The articles having been dried, are exposed in a stove for five hours, at 75° C, in a current of electrified air, or air containing a considerable quantity of ozone, for the oxidation of the linseed oil which fills the pores of the pulp. They are then plunged for an hour in a bath of linseed oil, castor oil, and colophony; exposed again in the stove to air and ozone, after which they are completely impermeable, flexible, and proof against acid.
The adaptability of paper for the construction of canoes has been proved by the strictest tests, and the canoes have been found to be practicable boats; but the manufacture of them has not been as prosperous an industry as might have been anticipated.
On the other hand, the application of paper in house-building has been crowned with success. A builder's establishment founded several years ago took for its device "Neither wood nor iron"; and its houses, built almost exclusively of pressed paper, are curious specimens of what may be done with that material. The element of the construction is a panel, usually three metres by one metre and sixty centimetres, and a tubular beam ten centimetres in thickness, and composed of two walls of pressed paper four millimetres in thickness, fixed upon a frame, likewise of paper. The pieces composing this frame are V or U shaped; and these devices, capable of giving extremely light joists or beams, are not one of the least original of the conceptions of the system. The elementary panels do not weigh more than forty kilogrammes apiece; they are easily handled, and they fit at their edges so as to constitute the wall. The roof is composed of similar panels fastened in pairs. They rest on the walls against which the corner-pieces of paper abut. Although the thrust is weak enough, the two parallel walls are connected by a number of tie-beams composed of thin wire of galvanized iron, particularly if the construction consists of a long hall without any bearing wall. By means of the double walls, which inclose a cushion of air all around the construction, we get houses nearly insensible to variations of temperature, and consequently very comfortable to live in. The floor is composed of panels about a metre and a half square, constituting a wall of paper six millimetres thick, nailed to V-shaped wing-beams.
The use of these houses may be particularly commended for temporary constructions. They are remarkably well adapted to
Hospital on Wheels. (Espitallier system.)
places used for exhibitions, for ambulance services, military campaigns, etc. Hospitals made upon this system appear to have given very satisfactory results. Besides the general advantages accruing from a rapid building, the particular fact may be taken account of that the paper used in the construction of the walls may be made with antiseptic water, which will communicate to it the precious quality of not harboring germs of infection.
[An ingenious portable hospital or barracks of paper, the invention of M. Espitallier, captain of engineers, is described in another number of La Nature, by M. J. Comportey. Its interior dimensions are sixteen by five metres, and it will accommodate twenty beds. Folded up, it forms a load for three two-horse trucks. When it is to be set up, the three trucks, the length of which is equal to the width of the building, are brought up so as to be parallel in line and a few metres distant from one another, and are arranged so that their floors, which are to form part of the floor of the building, shall be on a level. Light T-shaped joists of iron are stretched across the intervals, supported by trestles when necessary, to receive the paper panels completing the floor. The other details of the structure are substantially as described by M. Ratoin. The interior of this building is entirely satisfactory, without visible framework, and without posts to interfere with the arrangement of the beds or with the circulation of the air. The walls, and the ceiling, which is inclined according to the inclination of the roof, are closely jointed and varnished, and consequently easy to wash and disinfect. The only open joints are the vertical couplings, which can be inspected and cleansed by simply taking them apart. The windows are of wire gauze covered with a transparent coating so as to avoid the inconveniences of glass. Ventilation is effected through holes bored at the angle of the ceiling and the wall.—Ed. P. S. M.]
We do not purpose here to review all the new applications that have been made of paper, but have intended only to take notice of some of the principal ones, and to call attention to some of the improvements that have been made in them. To the other uses—in wagon-wheels, barrels, horseshoes, etc., mentioned in the beginning of this article—we may add a notice of the experiments that have been made in the use of paper in the manufacture of some articles of furniture, such as tables and folding chairs, the principal advantages of which evidently lie in their lightness. These experiments have been timid enough; but no long time will elapse before paper, which already has its masons and its carpenters, shall also have its cabinet-makers.—Translated for The Popular Science Monthly from La Nature.
Recent analyses of the air of larger towns, made by a committee of the British Association for the Advancement of Science, and reported by Mr. G. A. Bailey, show: 1. That in clear, breezy weather the amount of sulphurous acid is less than one milligramme per one hundred cubic feet of air. 2. That in anti-cyclonic periods it rises very considerably, and in times of fog, maxima of thirty-four and fifty milligrammes have been recorded for the worst districts of Manchester and London respectively. 3. That wherever an open space or a less densely populated area occurs there is a very marked diminution in the amount of impurities in the air. 4. That an increase in the amount of sulphurous acid is accompanied by at least as large an increase in the amount of organic impurities in the air. 5. That smoke, promoting as it does the formation of fog, and preventing free diffusion into the upper stratum of the air, must be regarded as the principal cause of the impure state of the atmosphere in large towns.