Chapter 3

The old and cumbersome methods of crushing oil seeds by mechanical means have during the last few years undergone a complete revolution. By the old process, the seed, having been flattened between a pair of stones, was afterward ground by edge stones, weighing in some cases as much as 20 tons, and working at about eighteen revolutions per minute. Having been sufficiently ground, the seed was taken to a kettle or steam jacketed vessel, where it was heated, and thence drawn--in quantities sufficient for a cake--in woollen bags, which were placed in a hydraulic press. From four to six bags was the utmost that could be got into the press at one time, and the cakes were pressed between wrappers of horsehair on similar material. All this involved a good deal of manual labor, a cumberstone plant, and a considerable expense in the frequent replacing of the horsehair wrappers, each of which involved a cost of about £4. The modern requirements of trade have in every branch of industry ruthlessly compelled the abandonment of the slow, easy-going methods which satisfied the times when competition was less keen. Automatic mechanical arrangements, almost at every turn, more effectually and at greatly increased speed, complete manufacturing operations previously performed by hand, and oil-seed crushing machinery has been no exception to the general rule. The illustrations we give represent the latest developments in improved oil-mill machinery introduced by Rose, Downs & Thompson, named the "Colonial" mill, and recently we had an opportunity of inspecting the machinery complete before shipment to Calcutta, where it is being sent for the approaching exhibition. As compared with the old system of oil-seed crushing, Messrs. Rose, Downs & Thompson claim for their method, among other advantages, a great saving in driving power, economy of space, a more perfect extraction of the oil, an improved branding of the cakes, a saving of 50 per cent. in the labor employed in the press-room, with also a great saving in wear and tear, while the process is equally applicable to linseed, cottonseed, rapeseed, or similar seeds. In addition to these improvements in the system, the "Colonial" mill has been specially designed in structural arrangement to meet the requirements of exporters. The machinery and engine are self-contained on an iron foundation, so that there is no need of skilled mechanics to erect the mill, nor of expensive stone foundations, while the building covering the mill can, if desired, be of the lightest possible description, as no wall support is required. The mill consists of the following machinery: A vertical steel boiler, 3 ft. 7 in. diameter, 8 ft. 1½ in. high, with three cross tubes 7½ in. diameter, shell 5/16 in. thick, crown 3/8 in. thick, uptake 9 in. diameter, with all necessary fittings, and where wood fuel is used extra grate area can be provided. This boiler supplies the steam not only for the engine, but also for heating and damping the seed in the kettle. The engine is vertical, with 8 in. cylinder and 12 in. stroke, with high speed governors, and stands on the cast iron bed-plate of the mill. This bed-plate, which is in three sections, is about 30 ft. long, and is planed and shaped to receive the various machines, which, when the top is leveled, can be fixed in their respective places by any intelligent man, and when the machines are in position they form a support for the shafting. The seed to be crushed is stored in a wooden bin, placed above and behind the roll frame hopper. The roll frame has four chilled cast iron rolls, 15 in. face, 12 in. diameter, so arranged as to subject the seed to three rollings, with patent pressure giving apparatus. These rolls are driven by fast and loose pulleys by the shaft above. After the last rolling the seed falls through an opening in the foundation plate in a screen driven from the bottom roll shaft by a belt. This conveys the seed in a trough to a set of elevators, which supply it continuously to the kettle. This kettle, which is 3 ft. 6 in. internal diameter and 20 in. deep, is made of cast iron and of specially strong construction. There is only one steam joint in it, and to reduce the liability of leakage this joint is faced in a lathe. The inside furnishings of the kettle are a damping apparatus with perforated boss, upright shaft, stirrer, and delivery plate, and patent slide. The kettle body is fitted with a wood frame and covered with felt, which is inclosed within iron sheeting. The crushed seed is heated in the kettle to the required temperature by steam from the boiler, and it is also damped by a jet of steam which is regulated by a wheel valve with indicating plate. When the required temperature has been obtained, the seed is withdrawn by a measuring box through a self-acting shuttle in the kettle bottom, and evenly distributed over a strip of bagging supported on a steel tray in a Virtue patent moulding machine, where it undergoes a compression sufficient to reduce it to the size that can be taken in by the presses, but not sufficient to cause any extraction of the oil. The seed leaves the moulding machine in the form of a thick cake from nine to eleven pounds in weight, and each press is constructed to take in twelve of these cakes at once. The press cylinders are 12 in. diameter and are of crucible cast steel. To insure strength of construction and even distribution of strain throughout the press, all the columns, cylinders, rams, and heads are planed and turned accurately to gauges, and the pockets that take the columns, in the place of being cast, as is sometimes usual, with fitting strips top and bottom, are solid throughout, and are planed or slotted out of the solid to gauges. The pressure is given by a set of hydraulic pumps made of crucible cast steel and bored out of the solid. One of the pump rams is 2½ in. diameter, and has a stroke of 7 in. This ram gives only a limited pressure, and the arrangements are such as to obtain this pressure upon each press in about fourteen seconds. This pump then automatically ceases running, and the work is taken up by a second plunger, having a ram 1 in. diameter and stroke of 7 in., the second pump continuing its work until a gross pressure of two tons per square inch is attained, which is the maximum, and is arrived at in less than two minutes. For shutting off the communication between the presses, the stop valves are so arranged that either press may be let down, or set to work without in the smallest degree affecting the other. The oil from the presses is caught in an oil tank behind, from which an oil pump, worked by an eccentric, forces it in any desired direction. The cakes, on being withdrawn from the press, are stripped of the bagging and cut to size in a specially arranged paring machine, which is placed off the bed-plate behind the kettle, and is driven by the pulley shown on the main shaft. The paring machine is also fitted with an arrangement for reducing the parings to meal, which is returned to the kettle, and again made up into cakes. The presses shown have corrugated press plates of Messrs. Rose, Downs & Thompson's latest type, but the cakes produced by this process can have any desired name or brand in block letters put upon them. The edges on the upper plate, it may be added, are found of great use in crushing some classes of green or moist seed. The plant, of which we give illustrations opposite, is constructed to crush about four tons of seed per day of eleven hours, and the manual labor has been so reduced to a minimum that it is intended to be worked by one man, who moulds and puts the twenty-four cakes into the presses, and while they are under pressure is engaged paring the cakes that have been previously pressed. In crushing castor-oil seed, a decorticating machine or separator can be combined with the mill, but in such a case the engine and boiler would require to be made larger.--_The Engineer_.

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APPARATUS FOR SEPARATING SUBSTANCES CONTAINED IN THE WASTE WATERS OF PAPER MILLS, ETC.

For extracting such useful materials as are contained in the waste waters of paper mills, cloth manufactories, etc., and, at the same time, for purifying such waters, Mr. Schuricht, of Siebenlehn, employs a sort of filter like that shown in the annexed Figs. 1 and 2, and underneath which he effects a vacuum.

The apparatus, A, is divided into two compartments, which are separated by a longitudinal partition. Above the stationary bottom, a, there is arranged a lattice-work grating or a strong wire cloth, b, upon which rests the filtering material, c, properly so called. The reservoir is divided transversely by several partitions, d, of different heights. The liquor entering through the leader, f, traverses the apparatus slowly, as a consequence of the somewhat wide section of the layer. But, in order that it may traverse the filtering material, it is necessary that, in addition to this horizontal motion, it shall have a downward one. As far as to the top of the partitions, d, there form in front of the latter certain layers which do not participate in the horizontal motion, but which can only move downward, as a consequence of the permeability of the bottom. It results from this that the heaviest solid particles deposit in the first compartment, while the others run over the first partition, d, and fall into one of the succeeding compartments, according to their degree of fineness, while the clarified water makes its exit through the spout, g. When the filtering layer, c, has become gradually impermeable, the cock, i, of a jet apparatus, k, is opened, in order to suck out the clarified water through the pipe, r.--_Dingler's Polytech. Journ., after Bull. Musée de l'Industrie_.

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LARGE BLUE PRINTS.

By W.B. PARSONS, JR., C.E.

I send you a description of a device that I got up for the N.Y., L.E., and W.R.R. division office at Port Jervis, by which I overcame the difficulties incident to large glasses. The glass was 58 inches long, 84 inches wide, and 3/8 inch thick. It was heavily framed with ash. In order to keep the back from warping out of shape, I had it made of thoroughly seasoned ash strips 1" x 1". Each strip was carefully planed, and then they were glued and screwed together, while across the ends were fastened strips with their grain running transversely. This back was then covered on side next to the glass with four thicknesses of common gray blanketing. Instead of applying the holding pressure by thumb cleats at the periphery, it was effected by two long pressure strips running across the back placed at about one quarter the length of the frame from the ends, and held by a screw at the center. The ends of these strips were made so as to fit in slots in the frame at a slight angle, so that as the pressure strips were turned it gave them a binding pressure at the same time. In other words, it is the same principle as is commonly used to keep backs in small picture frames. This arrangement, instead of holding the back at the edges only, and so allowing the center to fall away from the glass, distributed it evenly over the whole surface and always kept it in position. The frame was run in and out of the printing room on a little railway on which it rested on four grooved brass sheaves, one pair being at one end, while the other was just beyond the center, so the frame could be revolved in direction of its length without trouble. In order to raise the heavy back, I had a pulley-wheel fastened to the ceiling, through which a rope passed, with a ring that could be attached to a corresponding hook at the side of the back, in order to hoist it or lower it. Although that is an extremely large apparatus, yet by means of the above device it was worked easily and rapidly, and gave every satisfaction.

The solution used was of the same proportions as had been adopted in the other engineering offices of the road:

Citrate iron and ammonium 1-7/8 oz. Red prussiate potash (C.P.) 1-1/4 oz.

Dissolve separately in 4 oz. distilled water each, and mix when ready to use. But by putting mixture in dark bottle, and that in a tight box impervious to light, it can be kept two or three weeks.

In some frames used at the School of Mines for making large blue prints a similar device has been in use for several years. Instead, however, of the heavy and cumbrous back used by Mr. Parsons, a light, somewhat flexible back of one-quarter inch pine is employed, covered with heavy Canton flannel and several thicknesses of newspaper. The pressure is applied by light pressure strips of ash somewhat thicker at the middle than at the ends, which give a fairly uniform pressure across the width of the frame sufficient to hold the back firmly against the glass at all points. This system has been used with success for frames twenty-seven by forty-two inches, about half as large as the one described by Mr. Parsons. A frame of this size can be easily handled without mechanical aids. Care should be taken to avoid too great thickness and too much spring in the pressure strips, or the plate glass may be broken by excessive pressure. The strips used are about five-eighths of an inch thick at the middle, and taper to about three-eighths of an inch at the ends.

The formulæ for the solution given by Whittaker, Laudy, and Parsons are practically identical so far as the proportions of citrate of iron and ammonia and of red prussiate of potash, 3 of the former to 2 of the latter, but differ in the amount of water. Laudy's formula calls for about 5 parts of water to 1 of the salts, Whittaker's for 4 parts, and Parson's for a little more than 2 parts. The stronger the solution the longer the exposure required. With very strong solutions a large portion of the Prussian blue formed comes off in the washwater, and when printing from glass negatives the fine lines and lighter tints are apt to suffer. The blue color, however, will be deep and the whites clear. With weak solutions the blues will be fainter and the whites bluish. Heavily sized paper gives the best results. The addition of a little mucilage to the solution is sometimes an advantage, producing the same results as strength of solution, by increasing the amount adhering to the paper. With paper deficient in sizing the mucilage also makes the whites clearer.--_H.S.M., Sch. of M. Quarterly._

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HOUSE DRAINAGE AND REFUSE.

A course of lectures on sanitary engineering has been delivered during the past few weeks before the officers of the Royal Engineers stationed at Chatham, by Captain Douglas Galton, C.B., D.C.L., F.R.S.

The refuse which has to be dealt with, observed Captain Galton, whether in towns or in barracks or in camp, falls under the following five heads: 1, ashes; 2, kitchen refuse; 3, stable manure; 4, solid or liquid ejections; and 5, rainwater and domestic waste water, including water from personal ablutions, kitchen washing up, washings of passages, stables, yards, and pavements. In a camp you have the simplest form of dealing with these matters. The water supply is limited. Waste water and liquid ejection are absorbed by the ground; but a camp unprovided with latrines would always be in a state of danger from epidemic disease. One of the most frequent causes of an unhealthy condition of the air of a camp in former times has been either neglecting to provide latrines, so that the ground outside the camp becomes covered with filth, or constructing the latrines too shallow, and exposing too large a surface to rain, sun, and air. The Quartermaster-General's regulations provide against these contingencies; but I may as well here recapitulate the general principles which govern camp latrines. Latrines should be so managed that no smell from them should ever reach the men's tents. To insure this very simple precautions only are required:

1. The latrines should be placed to leeward with respect to prevailing winds, and at as great a distance from the tents as is compatible with convenience. 2. They should be dug narrow and deep, and their contents covered over every evening with at least a foot of fresh earth. A certain bulk and thickness of earth are required to absorb the putrescent gas, otherwise it will disperse itself and pollute the air to a considerable distance round. 3. When the latrine is filled to within 2 ft. 6 in. or 3 ft. of the surface, earth should be thrown into it, and heaped over it like a grave to mark its site. 4. Great care should be taken not to place latrines near existing wells, nor to dig wells near where latrines have been placed. The necessity of these precautions to prevent wells becoming polluted is obvious. Screens made out of any available material are, of course, required for latrines. This arrangement applies to a temporary camp, and is only admissible under such conditions.

A deep trench saves labor, and places the refuse in the most immediately safe position, but a buried mass of refuse will take a long time to decay; it should not be disturbed, and will taint the adjacent soil for a long time. This is of less consequence in a merely temporary encampment, while it might entail serious evils in localities continuously inhabited. The following plan of trench has been adopted as a more permanent arrangement in Indian villages, with the object of checking the frightful evil of surface pollution of the whole country, from the people habitually fouling the fields, roads, streets, and watercourses. Long trenches are dug, at about one foot or less in depth, at a spot set apart, about 200 or 300 yards from dwellings. Matting screens are placed round for decency. Each day the trench, which has received the excreta of the preceding day, is filled up, the excreta being covered with fresh earth obtained by digging a new trench adjoining, which, when it has been used, is treated in the same manner. Thus the trenches are gradually extended, until sufficient ground has been utilized, when they are plowed up and the site used for cultivation. The Indian plow does not penetrate more than eight inches; consequently, if the trench is too deep, the lower stratum is left unmixed with earth, forming a permanent cesspool, and becomes a source of future trouble. It is to be observed, however, that in the wet season these trenches cannot be used, and in sandy soil they do not answer. This system, although it is preferable to what formerly prevailed--viz., the surface defilement of the ground all round villages and of the adjacent water courses--is fraught with danger unless subsequent cultivation of the site be strictly enforced, because it would otherwise retain large and increasing masses of putrefying matter in the soil, in a condition somewhat unfavorable to rapid absorption. These arrangements are applicable only to very rough life or very poor communities.

The question of the removal of kitchen refuse, manure, etc., from barracks next calls for notice. The great principle to be observed in removing the solid refuse from barracks is that every decomposable substance should be taken away at once. This principle applies especially in warm climates. Even the daily removal of refuse entails the necessity of places for the deposit of the refuse, and therefore this principle must be applied in various ways to suit local convenience. In open situations, exposed to cool winds, there is less danger of injury to health from decomposing matters than there would be in hot, moist, or close positions. In the country generally there is less risk of injury than in close parts of towns. These considerations show that the same stringency is not necessarily required everywhere. Position by itself affords a certain degree of protection from nuisance. The amount of decomposing matter usually produced is also another point to be considered. A small daily product is not, of course, so injurious as a large product. Even the manner of accumulating decomposing substances influences their effect on health. There is less risk from a dung heap to the leeward than to the windward of a barrack. The receptacles in which refuse is temporarily placed, such as ash pits and manure pits, should never be below the level of the ground. If a deep pit is dug in the ground, into which the refuse is thrown in the intervals between times of removal, rain and surface water will mix with the refuse and hasten its decomposition, and generally the lowest part of the filth will not be removed, but will be left to fester and produce malaria. In all places where the occupation is permanent the following conditions should be attended to:

1. That the places of deposit be sufficiently removed from inhabited buildings to prevent any smell being perceived by the occupants. 2. That the places of deposit be above the level of the ground--never dug out of the ground. The floor of the ash pit or dung pit should be at least six inches above the surface level. 3. That the floor be paved with square sets, or flagged and drained. 4. That ash pits be covered. 5. That a space should be paved in front, so as to provide that the traffic which takes place in depositing the refuse or in removing it shall not produce a polluted surface.

In towns those parts of the refuse which cannot be utilized for manure or otherwise are burned. But this is an operation which, if done unskillfully, without a properly constructed kiln, may give rise to nuisance. One of the best forms of kiln is one now in operation at Ealing, which could be easily visited from London.

_The removal of excreta from houses._--The chief object of a perfect system of house drainage is the immediate and complete removal from the house of all foul and effete matter directly it is produced. The first object--viz., removal of foul matter, can be attained either by the water closet system, when carried out in this integrity; but it could, of course, be attained without drains if there was labor enough always available; and the earth closet or the pail system are modifications of immediate removal which are safe. Cesspools in a house do not fulfill this condition of immediate removal. They serve for the retention of excremental and other matters. In a porous soil it endangers the purity of the wells. The Indian cities afford numerous examples of subsoil pollution. The Delhi ulcer was traced to the pollution of the wells from the contaminated subsoil; and the soil in many cities and villages is loaded with niter and salt, the chemical results of animal and vegetable refuse left to decay for many generations, from the presence of which the well water is impure. There are many factories of saltpeter in India whose supplies are derived from this source; and during the great French wars, when England blockaded all the seaports of Europe, the First Napoleon obtained saltpeter for gunpowder from the cesspits in Paris. Cesspools are inadmissible where complete removal can be effected. Cesspits may, however, be a necessity in some special cases, as, for instance, in detached houses or a small detached barrack. Where they cannot be avoided, the following conditions as to their use should be enforced: