Chapter X: TECHNOLOGY.--Apparatus for Testing Champagne Bottles and (2)

Further, the springs tend to counteract any tendency to vibration that might be set up by the rapid reciprocation of the cross head, cutters, and their attendant parts. Mounted also on the main shaft is one of a pair of reversed cone drums. These, with their accompanying belt and its adjusting gear, worked by a hand wheel and traversing screw, as shown, serve to adjust the speed of the feed rollers, so as to suit the different lengths of the intermediate travel or "skip" of the dough-carrying web.

Provision is made for taking up the slack of this belt by mounting the spindle of the outer coned drum in bearings adjustable along a circular path struck from the axis of the lower feed roller as a center, thus insuring a uniform engagement between the teeth of the small pinion and those of the spur wheel with which the drum and roller are respectively provided.

The webs for carrying forward the dough between the different operations pass round rollers, which are each operated by an adjustable silent clutch feed, in place of the usual ratchet and pawl mechanism. Movement is given to each feed by the connecting links shown, to each of which motion is in turn imparted by the bell crank lever placed beside the eccentric. This lever is actuated by a crank pin on the main shaft, working into a block sliding in a slot in the shorter or horizontal arm of the lever, while a similar but adjustable block, sliding in the vertical arm, serves to impart the motion of the lever to the system of connecting links, the adjustable block allowing of a longer or shorter stroke being given to the different feeds, as desired.

The scraps are carried over the roller in rear of the cutters, and so to a scrap pan, while the stamped biscuits pass by a lower web into the pans. These pans are carried by two endless chains, provided with pins, which take hold of the pans and carry them along in the proper position. The roller over which these chains pass is operated by a silent clutch, and in order to give an additional motion to the chains when a pan is full, and it is desired to bring the next pan into position, an additional clutch is caused to operate upon the roller. This clutch is kept out of gear with its pulley by means of a projection upon it bearing against a disk slightly greater in diameter than the pulley, and provided with two notches, into which the projection passes when the additional feed is required.

The makers, H. Edwards & Co., Liverpool, have run one of these machines easily and smoothly at a hundred revolutions per minute, at which speed, and when absorbing about 3.5 horse power, the output would equal 4,000 small biscuits per minute.--_Industries._

* * * * *

IMPROVED CREAM SEPARATOR.

A hand separator of this type was exhibited at the Royal Show at Newcastle by the Aylesbury Dairy Company, of 31 St. Petersburg Place, Bayswater, England.

Fig. 1 is a perspective view of the machine, Fig. 2 being a vertical section. The drums of these machines, which make 2,700 revolutions per minute for the large and 4,000 for the small one, have a diameter of 27 in. and 15½ in. respectively, and are capable of extracting the cream from 220 and 115 gallons of milk per hour. These drums are formed by hydraulic pressure from one piece of sheet steel. To avoid the possibility of the machines being overdriven, which might happen through the negligence of the attendant or through the governing gear on the engine failing to act, an ingenious controlling apparatus is fixed to the intermediate motion of the separator as shown in Fig. 3. This apparatus consists of a pair of governor balls pivoted near the center of the arms and attached to the main shaft of the intermediate gear by means of a collar fixed on it. The main shaft is bored out sufficiently deep to admit a steel rod, against which bear the three ends of the governor arms. The steel rod presses against the counterbalance, which is made exactly the right weight to withstand the force tending to raise it, when the intermediate motion is running at its designed speed. The forks between which the belt runs are also provided with a balance weight. This brings them to the loose pulley, unless they are fixed by means of the ratchet. Should the number of revolutions of the intermediate increase beyond the correct amount, the extra centrifugal force imparted to the governor balls enables them to overcome the balance weight, and in raising this they raise the arm. This arm striking against the ratchet detent releases the balance weight, and the belt is at once brought on to the loose pulley.

The steel drum is fitted with an internal ring at the bottom (see Fig. 2), into which the milk flows, and from which it is delivered, by three apertures, to the periphery of the drum, thus preventing the milk from striking against the cone of the drum, and from mixing with the cream which has already been separated. The upper part of the drum is fitted with an annular flange, about 1½ in. from the top, reaching to within one-sixteenth of an inch of the periphery. After the separation of the skim milk from the cream, the former passes behind and above this flange through the aperture, B, and is removed by means of the tube, D, furnished with a steel tip projecting from the cover of the machine into the space between the top of the drum and the annular flange, a similar tube, F, reaching below this flange, removing the cream which collects there. The skim milk tube is provided with a screw regulator, the function of which is to enable cream of any desired consistency to be obtained, varying with the distance between the skim milk and cream points from the center of the drum. Another point about these tubes is their use as elevating tubes for the skim, milk and cream, as, owing to the velocity at which the drum is rotating, the products can be delivered by these tubes at a height of 8 or 10 feet above the machine if required, thus enabling scalding and cooling of either to be carried on while the separator is at work, and saving hand labor.--_Iron._

* * * * *

GAS FROM OIL.

At the twenty-fourth annual meeting of the Gas Institute, which was recently held in Glasgow, Dr. Stevenson Macadam, F.R.S.E., lecturer on chemistry, Edinburgh, submitted the first paper, which was on "Gas from Oil."

He said that during the last seventeen years he had devoted much attention to the photogenic or illuminating values of different qualities of paraffin oils in various lamps, and to the production of permanent illuminating gas from such oils. The earlier experiments were directed to the employment of paraffin oils as oils, and the results proved the great superiority of the paraffin oils as illuminating agents over vegetable and animal oils, alike for lighthouse and ordinary house service.

The later trials were mainly concerned with the breaking up of the paraffin oils into permanent illuminating gas. Experiments were made at low heats, medium heats, and high heats, which proved that, according to the respective qualities of the paraffin oils employed in the trials, there was more or less tendency at the lower heats to distill oil instead of permanent gas, while at the high heats there was a liability to decarbonize the oil and gas, and to obtain a thin gas of comparatively small illuminating power. When, however, a good cherry red heat was maintained, the oils split up in large proportion into permanent gas of high illuminating quality, accompanied by little tarry matter, and with only a slight amount of separated carbon or deposited soot.

The best mode of splitting up the paraffin oils, and the special arrangements of the retort or distilling apparatus, also formed, he said, an extensive inquiry by itself. In one set of trials the oil was distilled into gaseous vapor, and then passed through the retort. In another set of experiments, the oil was run into or allowed to trickle into the retorts, while both modes of introducing the oil were tried in retorts charged with red hot coke and in retorts free from coke.

Ultimately, it was found that the best results were obtained by the more simple arrangement of employing iron retorts at a good cherry red heat, and running in the oil as a thin stream direct into the retort, so that it quickly impinged upon the red hot metal, and without the intervention of any coke or other matter in the retorts. The paraffin oils employed in the investigations were principally: (1) Crude paraffin oil, being the oil obtained direct from the destructive distillation of shale in retorts; (2) green paraffin oil, which is yielded by distilling or re-running the crude paraffin oil, and removing the lighter or more inflammable portion by fractional distillation; and (3) blue paraffin oil, which is obtained by rectifying the twice run oil with sulphuric acid and soda, and distilling off the paraffin spirit, burning oil, and intermediate oil, and freezing out the solid paraffin as paraffin scale. The best practical trials were obtained in Pintsch's apparatus and in Keith's apparatus.

After describing both of these, Dr. Macadam went on to give in great detail the results obtained in splitting up blue paraffin oil into gas in each apparatus. He then said that these experimental results demonstrated that Pintsch's apparatus yielded from the gallon of oil in one case 90.70 cubic feet of gas of 62.50 candle power, and in the second case 103.36 cubic feet of 59.15 candle gas, or an average of 97.03 cubic feet of 60.82 candle power gas.

In both cases, the firing of the retorts was moderate, though in the second trial greater care was taken to secure uniformity of heat, and the oil was run in more slowly, so that there was more thorough splitting up of the oil into permanent gas. The gas obtained in the two trials was of high quality, owing to its containing a large percentage of heavy hydrocarbons, of which there were, respectively, 39.25 and 37.15 per cent., or an average of 38.2 per cent., while the sulphureted hydrogen was nothing, and the carbonic acid a mere trace. Besides testing the gas on the occasion of the actual trials, he had also examined samples of the gas which he had taken from various cylinders in which the gas had been stored for several months under a pressure of ten atmospheres, and in all cases the gas was found to be practically equal to the quantity mentioned, and hence of a permanent character.

By using Keith's apparatus the results obtained were generally the same, with the exception that an average of 0.27 per cent. of carbonic acid gas and decided proportions of sulphureted hydrogen were found to be present in the gas. Dr. Macadam devoted some remarks to the consideration of the question as to how far the gas obtained from the paraffin oil represented the light power of the oil itself, and then he proceeded to say that, taking the crude paraffin oil at 2d. a gallon, and with a specific gravity of 850 (water = 1,000), or 8½ lb. to the gallon, there were 264 gallons to the ton, at a cost of £2 4s. per ton. The sperm light from the ton of oil as gas being 3,443 lb., he reckoned that fully 6 lb. of sperm light were obtained from a pennyworth of the crude oil as gas.

Then, taking the blue paraffin oil at 4d. per gallon, and there being 255 gallons to the ton, it was found that the cost of one ton was £4 5s., and as the sperm light of a ton of that oil as gas was 5,150 lb., it was calculated that 5 lb. of sperm light were yielded in the gas from a pennyworth of the blue oil. The very rich character of the oil gas rendered it unsuitable for consumption at ordinary gas jets, though it burned readily and satisfactorily at small burners not larger than No. 1 jets.

In practical use it would be advisable to reduce the quality by admixture with thin and feeble gas, or to employ the oil gas simply for enriching inferior gases derived from the more common coals. On the question of dilution, he said that he preferred to use carbonic oxide and hydrogen, and most of the remainder of his paper was devoted to an explanation of the best mode of preparing those gases (water gases).

He concluded by saying: The employment of paraffin oil for gas making has advantages in its favor, in the readiness of charging the retorts, as the oil can be run in continuously for days at a time, and may be discontinued and commenced again without opening, clearing out residual products, recharging and reclosing the retorts. There is necessarily, therefore, less labor and cost in working, and as the gas is cleaner or freer from impurities, purifying plant and material will be correspondingly less. Oil gas is now employed for lighthouse service in the illumination of the lanterns on Ailsa Craig and as motive power in the gas engines connected with the fog horns at Langness and Ailsa Craig lighthouse stations. It is also used largely in the lighting of railway carriages. Various populous places are now introducing oil gas for house service, and he felt sure that the system is one which ought to commend itself for its future development to the careful consideration and practical skill of the members of the Gas Institute.

* * * * *

THE MANUFACTURE OF SALT NEAR MIDDLESBROUGH.[1]

[Footnote 1: Abstract of paper read before the Institution of
Civil Engineers, May 17, 1887.]

By Sir LOWTHIAN BELL, Bart., F.R.S.

The geology of the Middlesbrough salt region was first referred to, and it was stated that the development of the salt industry in that district was the result of accident. In 1859, Messrs. Bolckow & Vaughan sank a deep well at Middlesbrough, in the hope of obtaining water for steam and other purposes in connection with their iron works in that town, although they had previously been informed of the probably unsuitable character of the water if found. The bore hole was put down to a depth of 1,200 feet, when a bed of salt rock was struck, which proved to have a thickness of about 100 feet. At that time one-eighth of the total salt production of Cheshire was being brought to the Tyne for the chemical works on that river, hence the discovery of salt instead of water was regarded by some as the reverse of a disappointment. The mode of reaching the salt rock by an ordinary shaft, however, failed, from the influx of water being too great, and nothing more was heard of Middlesbrough salt until a dozen years later, when Messrs. Bell Brothers, of Port Clarence, decided to try the practicability of raising the salt by a method detailed in the paper. A site was selected 1,314 yards distant from the well of Messrs. Bolckow & Vaughan, and the Diamond Rock Boring Company was intrusted with the work of putting down a hole in order to ascertain whether the bed of salt extended under their land. This occupied nearly two years, when the salt, 65 feet in thickness, was reached at a depth of 1,127 feet. Other reasons induced the owners of the Clarence iron works to continue the bore hole for 150 feet below the bed of salt; a depth of 1,342 feet from the surface was then reached. During the process of boring, considerable quantities of inflammable gas were met with, which, on the application of flame, took fire at the surface of the water in the bore hole. The origin of this gas, in connection with the coal measures underlying the magnesian limestone, will probably hereafter be investigated.

For raising the salt, recourse was had to the method of solution, the principle being that a column of descending water should raise the brine nearly as far as the differences of specific gravity between the two liquids permitted--in the present case about 997 feet. In other words, a column of fresh water of 1,200 feet brought the brine to within 203 feet of the surface. For the practical application of this system a hole of say 12 inches in diameter at the surface was commenced, and a succession of wrought iron tubes put down as the boring proceeded, the pipes being of gradually decreasing diameter, until the bottom of the salt bed was reached. The portion of this outer or retaining tube, where it passed through the bed of salt, was pierced with two sets of apertures, the upper edge of the higher set coinciding with the top of the seam, and the other set occupying the lower portion of the tube. Within the tube so arranged, and secured at its lower extremity by means of a cavity sunk in the limestone, a second tube was lowered, having an outer diameter from two to four inches less than the interior diameter of the first tube. The latter served for pumping the brine. The pump used was of the ordinary bucket and clack type, but, in addition, at the surface, there was a plunger, which served to force the brine into an air vessel for the purposes of distribution. The bucket and clack were placed some feet below the point to which the brine was raised by the column of fresh water descending in the annulus formed between the two tubes. In commencing work, water was let down the annulus until the cavity formed in the salt became sufficiently large to admit of a few hours' pumping of concentrated brine. On the machinery being set in motion, the stronger brine was first drawn, which, from its greater specific gravity, occupied the lower portion of the cavity. As the brine was raised, fresh water flowed down. The solvent power of the newly admitted water was of course greater than that of water partially saturated, and being also lighter it occupied the upper portion of the excavated space. The combined effect was to give the cavity the form of an inverted cone. The mode of extraction thus possessed the disadvantage of removing the greatest quantity of the mineral where it was most wanted for supporting the roof, and had given rise to occasional accidents to the pipes underground. These were referred to in detail, and the question was started as to possible legal complications arising hereafter from new bore holes put down in close proximity to the dividing line of different properties, the pumping of brine formed under the conditions described presenting an altogether different aspect from the pumping of water or natural brine.

The second part of the paper referred to the uses to which the brine was applied, the chief one being the manufacture of common salt. For this purpose the brine, as delivered from the wells, was run into a large reservoir, where any earthy matter held in suspension was allowed to settle. The clear solution was then run into pans sixty feet long by twenty feet wide by two feet deep. Heat was applied at one end by the combustion of small coal, beyond which longitudinal walls, serving to support the pan and to distribute the heat, conducted the products of combustion to the further extremity, where they escaped into the chimney at a temperature of from 500° to 700° Fahr. On the surface of the heated brine, kept at 196° Fahr., minute cubical crystals speedily formed. On the upper surface of these, other small cubes of salt arranged themselves in such a way that, in course of time, a hollow inverted pyramid of crystallized salt was formed. This ultimately sank to the bottom, where other small crystals united with it, so that the shape became frequently completely cubical. Every second day the salt was "fished" out and laid on drainers to permit the adhering brine to run back into the pans. For the production of table salt the boiling was carried on much more rapidly, and at a higher temperature than for salt intended for soda manufacture. The crystals were very minute, and adhered together by the solidification of the brine, effected by exposure on heated flues. For fishery purposes the crystals were preferred very coarse in size. These were obtained by evaporating the brine more slowly and at a still lower temperature than when salt for soda makers was required. At the Clarence works experiments had been made in utilizing surplus gas from the adjacent blast furnaces, instead of fuel, under the evaporating pans, the furnaces supplying more gas than was needed for heating air and raising steam for iron making. By means of this waste heat, from 200 to 300 tons of salt per week were now obtained.

The paper concluded with some particulars of the soda industry. The well-known sulphuric acid process of Leblanc had stood its ground for three-quarters of a century in spite of several disadvantages, and various modes of utilizing the by-products having been from time to time introduced, it had until recent years seemed too firmly established to fear any rivals. About seven years ago, however, Mr. Solvay, of Brussels, revived in a practical form the ammonia process, patented forty years ago by Messrs. Hemming & Dyar, but using brine instead of salt, and thus avoiding the cost of evaporation. This process consisted of forcing into the brine currents of carbonic acid and ammoniacal gases in such proportions as to generate bicarbonate of ammonia, which, reacting on the salt of the brine, gave bicarbonate of soda and chloride of ammonium. The bicarbonate was placed in a reverberatory furnace, where the heat drove off the water and one equivalent of carbonic acid, leaving the alkali as monocarbonate. Near Middlesbrough, the only branch of industry established in connection with its salt trade was the manufacture of soda by an ammonia process, invented by Mr. Schloesing, of Paris. The works were carried on in connection with the Clarence salt works. It was believed that the total quantity of dry soda produced by the two ammonia processes, Solvay's and Schloesing's, in this country was something under 100,000 tons per annum, but this make was considerably exceeded on the Continent.

* * * * *

COTTON INDUSTRIES OF JAPAN.

The cotton plant principally cultivated in Japan is of the species known as _Gossypium herbaceum_, resembling that of India, China, and Egypt. The plant is of short stature, seldom attaining a growth of over two feet; the flower is deciduous, with yellow petals and purple center, and the staple is short, but fine. It is very widely cultivated in Japan, and is produced in thirty-seven out of the forty-four prefectures forming the empire, but the best qualities and largest quantities are grown in the southern maritime provinces of the mainland and on the islands of Kiusiu and Shikoku. Vice consul Longford, in his last report, says that the plant is not indigenous to Japan, the seed having been first imported from China in the year 1558. There are now many varieties of the original species, and the cultivation of the plant varies in its details in different localities. The variations are, however, mostly in dates, and the general grinding principles of the several operations are nearly the same throughout the whole country. The land best suited for cotton growing is one of a sandy soil, the admixture of earth and sand being in the proportion of two parts earth to one of sand. During the winter and spring months, crops of wheat or barley are raised on it, and it is when these crops have attained their full height during the month of May that the cotton is sown. About fifty days prior to the sowing a manure is prepared consisting of chopped straw, straw ashes, green grass, rice, bran, and earth from the bottom of the stagnant pools. These ingredients are all carefully mixed together in equal proportions, and the manure thus made is allowed to stand till required for use. Ten days before the time fixed for sowing, narrow trenches, about one inch in depth, are dug in the furrows, between the rows of standing wheat or barleys and the manure is liberally sprinkled along them by hand. For one night before sowing the seed is steeped in water. It is then taken out, slightly mixed with straw ashes, and sown in the trenches at intervals of a few inches. When sown, it is covered with earth to the depth of half an inch, and gently trampled down by foot. Four or five days after sowing, the buds begin to appear above the earth, and almost simultaneously the wheat or barley between which they grow is ripe for the sickle. While the latter is being harvested, the cotton may be left to itself, but not for very long. The buds appear in much larger numbers than the soil could support if they were allowed to grow. They have accordingly to be carefully thinned out, so that not more than five or six plants are left in each foot of length. The next process is the sprinkling of a manure composed of one part night soil and three parts water, and again, subsequent to this, there are two further manurings; one of a mixture of dried sardines, lees of oil, and lees of rice beer, which is applied about the middle of June, when the plant has attained a height of four inches; and again early in July, when the plant has grown to a height of six or seven inches, a further manuring of night soil, mixed with a larger proportion of water than before. At this stage the head of the plant is pinched off with the fingers, in order to check the excessive growth of the stem, and direct the strength into the branches, which usually number five or six. From these branches minor ones spring, but the latter are carefully pruned off as they appear. In the middle of August the flowers begin to appear gradually. They fall soon after their appearance, leaving in their place the pod or peach (_momo_), which, after ripening, opens in October by three or four valves and exposes the cotton to view. The cotton is gathered in baskets, in which it is allowed to remain till a bright, sunshiny day, when it is spread out on mats to dry and swell in the sun for two or three days. After drying, the cotton is packed in bags made of straw matting, and either sold or put aside until such time as the farmer's leisure from other agricultural operations enables him to deal with it. The average yield of cotton in good districts in Japan is about 120 lb. to the acre, but as cotton is only a secondary crop, this does not therefore represent the whole profit gained by the farmer from his land. The prefectures in which the production is largest are Aichi on the east coast, Osaka, Hiogo, Hiroshima, and Yamaguchi on the inland sea, and Fukui and Ishikawa on the west coast. Vice-consul Longford says that the manufacture of cotton in Japan is still in all its stages largely a domestic one. Gin, spindle, and loom are all found in the house of the farmer on whose land the cotton is grown, and not only what is required for the wants of his own family is spun and woven by the female members thereof, but a surplus is also produced for sale.

Several spinning factories with important English machinery have been established during the last twenty years, but Consul Longford says that he has only known of one similar cotton-weaving factory, and that has not been a successful experiment. Other so called weaving factories throughout the country consist only of a collection of the ordinary hand looms, to the number of forty or fifty, scarcely ever reaching to one hundred, in one building or shed, wherein individual manufacturers have their own special piece goods made.

The first operation in the manufacture is that of ginning, which is conducted by means of a small implement called the _rokuro_, or windlass. This consists of two wooden rollers revolving in opposite directions, fixed on a frame about 12 inches high and 6 inches in width, standing on a small platform, the dimensions of which slightly exceed that of the frame. The operator, usually a woman, kneels on one side of the frame, holding it firm by her weight, works the roller with one hand, and with the other presses the cotton, which she takes from a heap at her side, between the rollers. The cotton passes through, falling in small lumps on the other side of the frame, while the seeds fall on that nearest the woman. The utmost weight of unginned cotton that one woman working an entire day of ten hours can give is from 8 lb. to 10 lb., which gives, in the end, only a little over 3 lb. weight of ginned cotton, and her daily earnings amount to less than 2d. A few saw gins have been introduced into Japan during the last fifteen years, but no effort has been made to secure their distribution throughout the country districts. After ginning, a certain proportion of the seed is reserved for the agricultural requirements of the following year, and the remainder is sent to oil factories, where it is pressed, and yields about one-eighth of its capacity in measurement in oil, the refuse, after pressing, being used for manure. The ginning having been finished in the country districts, the cotton is either packed in bales and sent to the dealers in the cities, or else the next process, that of carding, is at once proceeded with on the spot.

This process is almost as primitive as that of the ginning. A long bamboo, sufficiently thin to be flexible, is fastened at its base to a pillar or the corner of a small room. It slopes upward into the center of the room, and from its upper end a hempen cord is suspended. To this is fastened the "bow," an instrument made of oak, about five feet in length, two inches in circumference, and shaped like a ladle. A string of coarse catgut is tightly stretched from end to end of the bow, and this is beaten with a small mallet made of willow, bound at the end with a ring of iron or brass. The raw cotton, in its coarse state, is piled on the floor just underneath the string of the bow. The string is then rapidly beaten with the mallet, and as it rises and falls it catches the rough cotton, cuts it to the required degree of fineness, removes impurities from it, and flings it to the side of the operator, where it falls on a hempen net stretched over a four-cornered wooden frame. The spaces of the net are about one-quarter of an inch square, and through these any particles of dust that may still have adhered to the cotton fall to the floor, leaving piled on top of the net the pure cotton wool in its finished state. This work is always performed by a man, and by assiduous toil throughout a long day, one man can card from ten to twenty pounds weight of raw cotton. Payment is made in proportion to the work done, and in the less remote country districts is at the rate of about one penny for each pound carded. As regards spinning and weaving, in the first of these branches of cotton manufacture the Japanese have largely had recourse to the aid of foreign machinery, but it is still to a much greater extent a domestic industry, or at best carried on like weaving in the establishments of cotton traders, in which a number of workers, varying from 20 to 100 or more, each with his own spinning wheel, are collected together. Consul Longford says the spinning wheel used in Japan differs in no respect from that used in the country 300 years ago or (except that bamboo forms an integral part of the materials of which it is made) from that used in England prior to the invention of the jenny. The cost of one of the wheels is about 9d., it will last for five or six years, and with it a woman of ordinary skill can spin about 1 lb. of yarn in a day of ten hours, earning thereby about 2d. There are at present in various parts of Japan, in all, 21 spinning factories worked by foreign machinery. Of four of these there is no information, but of the remainder, one has 120 spindles; eleven, 2,000 spindles; two, 3,000 spindles; two, 4,000 spindles; and one, 18,000 spindles.--_Journal Soc. of Arts._

* * * * *

[Continued from SUPPLEMENT, No. 612, page 9774.]

CENTRIFUGAL EXTRACTORS.

By ROBERT F. GIBSON.

SUGAR MACHINES.--Besides separating the crystalline sugar and the sirup, secondary objects are to wash the crystals and to pack them in cakes. The cleansing fluid or "white liquor" is introduced at the center of the basket and is hurled against and passes through the sugar wall left from draining. The basket may be divided into compartments and the liquor guided into each. The compartments are removable boxes and are shaped to give bars or cakes or any form desired of sugar in mass. These boxes being removable cannot fit tightly against the liquor guides, and the liquor is apt to escape. This difficulty is overcome by giving the guides radial movement or by having rubber packing around the edges.

Sugar machines proper are of two kinds--those which are loaded, drained and then unloaded and those which are continuous in their working. The various figures preceding are of the first kind, and what has been said of vibrations applies directly to these.

The general advantages claimed for continuous working over intermittent are--that saving is made of time and motive power incident to introducing charge and developing velocity, in retarding and stopping, and in discharging; that, as the power is brought into the machine continuously, no shifting of belts or ungearing is necessary; and that there are less of the dangers incident to variable motion, either in the machine itself or the belting or gearing. The magma (the mixture of crystalline sugar and sirup) is fed in gradually, by which means it is more likely to assume a position of equilibrium in the basket.

There are two methods of discharging in continuous working--the sugar is thrown out periodically as the basket fills, or continuously. In neither case is the speed slackened. In the first either the upper half of the basket has an upward motion, on the lower half a downward motion (Pat. 252,483); and through the opening thus made the sugar is thrown. Fig. 22 (R.B. Palmer & Sons) is a machine of this kind. The bottom, B, with the cone distributor, _a_, have downward motion.

Continuous discharge of the second kind may be brought about by having a scoop fixed to the curb (or casing), extending down into the basket and delivering the sugar over the side (Pat. 144,319). Another method will be described under "Beet Machines."

BASKET.--The construction of the basket is exceedingly important. Hard experience has taught this. When centrifugals were first introduced, users were compelled by law to put them below ground; for they frequently exploded, owing to the speed being suddenly augmented by inequalities in the running of the engine or to the basket being too weak to resist the centrifugal force of the overcharge. Increasing the thickness merely adds to the centrifugal force, and hence to the danger, as even a perfectly balanced basket may sever.

One plan for a better basket was to have more than one wall. For example, there might be an inner wall of perforated copper, then one of wire gauze, and then another of copper with larger perforations. Another plan was to have an internal metallic cloth, bearing against the internally projecting ridges of the corrugations of the basket wall. A further complication is to give this internal gauze cylinder a rotation relative to the basket.

The basket wall has been variously constructed. In one case it consists of wire wound round and round and fastened to uprights, commonly known as the "wire basket;" in another case of a periphery without perforations, but spirally corrugated and having an opening at the bottom for the escape of the extracted liquid; in still another of a series of narrow bars or rings, placed edgewise, packed as close as desired. An advantage of this last style is that it is easily cleaned.

The best basket consists of sheet metal with bored perforations and having bands or flanges sprung on around the outside. The metal is brass, if it is apt to be corroded; if not, sheet iron. The perforations may be round, or horizontally much longer than wide vertically. One method for the manufacture of the basket wall (Pat. 149,553) is to roll down a plate, having round perforations, to the required thickness, causing narrowing and elongation of the holes and at the same time hardening the plate by compacting its texture. Long narrow slots are well adapted to catch sugar crystals, and this is not an unimportant point. Round perforations are usually countersunk. Instead of flanges, wire bands have been used, their lapping ends secured by solder.

As to comparative wear, it maybe remarked that one perforated basket will outlast three wire ones.

As to size, sugar baskets vary from 80 inches in diameter by 14 in. depth to 54 by 24. They are made, however, in England as large as 6 feet in diameter--a size which can be run only at a comparatively slow speed.

A peculiar complication of basket deserves notice (Pat. 275 874). It had been noticed that when a charge of magma was put into a centrifugal in one mass, the sugar wall on the side of the basket was apt to form irregularly, too thick at base and of varied color. To remedy this it was suggested to have within and concentric with the basket a charger with flaring sides, into which the mixture was to be put. When this charger reached a certain rotary velocity, the magma would be hurled out over the edge by centrifugal force and evenly distributed on the wall of the main basket.

SPINDLE.--The spindle as now made is solid cast steel, and the considerations governing its size, form, material, etc., are identical with those for any spindle. In order that the basket might be replaced by another after draining, the shaft has been made telescopic, but at the expense of stability and rigidity. In Fig. 16 is shown a device to avoid crystallizations, which are apt to occur in large forgings, and would prove fatal should they creep into the upper part of the spindle proper in a hanging machine. It consists of the secondary spindle, _c_.

DISCHARGING.--The drained sugar may either be lifted over the top of the basket (in machines which stop to be emptied), or be cast through openings in the bottom provided with valves. A section of the best form of valve may be seen in Figs. 15 and 17. Fig. 23 is a plan of the openings. The valve turns on the basket bearing. It may be constructed to open in the same direction in which the basket turns; so that when the brake is put on, the inertia of the valve operates to open it and while running to keep it closed. There are many other styles, but no other need be mentioned.

CASING.--The different styles of casing may be seen by reference to the various drawings. In one machine (not described) the casing is rigidly fixed to the basket, space enough being left between the bottom of the basket and the bottom of the casing to hold all the molasses from a charge. This arrangement merely adds to the bulk of the revolving parts, and no real advantage is gained.

BEARINGS.--The various styles of bearings can be seen by reference to the figures. One which deserves special attention is shown in Fig. 16 and Fig. 19. In one case it consists of loose disks, in the other of loose washers, rotating on one another. They are alternately of steel and hard bronze (copper and tin).

"There is probably no machine so little understood or so imperfectly constructed by the common manufacturer of sugar supplies as the high speed separator or centrifugal." Unless the product of experience and good workmanship, it is a dangerous thing at high velocities. Besides, its usual fate is to have an incompetent workman assigned to it, who does not use judgment in charging and running. So that designers and manufacturers have been forced not only to take into account the disturbing forces inherent in revolving bodies, but also to make allowance for poor management in running and neglect in cleaning.

CANE AND BEET MACHINES.--The first step in the process of sugar making is the extraction of the juice from the beet or cane. This juice is obtained by pressure. The operation is not usually, but may be, performed in a special kind of centrifugal. One style (Pat. 239,222) consists of a conical basket with a spiral flange within on the shaft, and turning on the shaft, and having a slight rotary motion relative to the basket. The material is fed in and moves downward under increased pressure, the sirup released flying out through the perforations of the basket, the whole revolving at high velocity. The solid portion falls out at the bottom. Another plan suggested (Pat. 343,932) is to let a loose cover of an ordinary cylindrical basket screw itself down into the basket, by reason of its slower velocity (owing to inertia), causing pressure on the charge.

Various other applications of the different styles of sugar machines are the defibration of raw sugar juice, freeing beet crystals of objectionable salts, freeing various crystals of the mother liquor, drying saltpeter.

DRIERS.--Another important division of this first class of centrifugals is that of driers or, as they are variously styled, whizzers, wringers, hydro-extractors. The charge in these is never large in weight compared to a sugar charge, and its initial distribution can be made more symmetrical. The uses of driers are various, such as extracting water from clothes, cloth, silk, yarns, etc. Water may be introduced at the center of the basket from above or below to wash the material before draining. A typical form of drier is shown in Fig. 24. (Pat. Aug. 22, 1876--W.P. Uhlinger.) Baskets have been made removable for use in dyeing establishments, basket and load together going into dyeing vat. Yarn and similar material can be drained by a method analogous to that of hanging it upon sticks in a room and allowing the water to drip off. It is suspended from short sticks, which are held in horizontal layers around the shaft in the basket, and the action is such during the operation as to cause the yarn to stand out in radial lines.

Driers are not materially different from sugar machines. Any of the devices before enumerated for meeting vibrations in the latter may be applied to the former. There is one curious invention which has been applied to driers only (Pat. 322,762--W.H. Tolhurst). See Fig. 25. A convex shaft-supporting step resting on a concave supporting base, with the center of its arc of concavity at the center of the upper universal joint, has been employed, and its movements controlled by springs, but the step was apt to be forced from its support. The drawing shows the improvement on this, which is to give the shaft-supporting step a less radius of curvature.

An interesting form of drier has its own motor, a little steam engine, attached to the frame of the machine. See Fig 24. This of course demands fixed bearings. The engine is very small. One size used is 3"×4". When a higher velocity of basket is required, we have the arrangement in Fig. 26.

MOTORS.--This naturally introduces the subject of motive power. We may have the engine direct acting as above, or the power may be brought on by belting. Fig. 27 shows a drier with pulley for belting. Fig. 28 (W.H. Tolhurst) shows a very common arrangement of belting and also the fast and loose pulleys. When the heaviest part of the engine is so far from the vertical shaft as to overhang the casing on one side, there is apt to be an objectionable tremor. To remedy this, it is suggested to put these heavy parts as near the shaft as possible. It has been suggested also to use the Westinghouse type of engine, although the type shown in Fig. 24 works faultlessly in practice.

One plan (Pat. 346,030), designed to combine the advantages of a direct acting motor and an oscillating shaft, mounts the whole machine, motor and all, on a rocking frame. The spindle is of course in fixed bearings in the frame. However, the plan is not practical.

In driers the direct acting engine has many advantages over the belt. The atmosphere is always very moist about a whizzer, and there are frequently injurious fumes. The belt will be alternately dry and wet, stretched and limp, and wears out rapidly and is liable to sever. In all machines in which the shaft oscillates, if the center of oscillation does not lie in the central plane of the belt, the tension of the latter is not uniform. This affects badly both the belt and the running. A reference to the various figures will show the best position for the pulley.

The greatest difficulty experienced with belting is in getting up speed and stopping. The basket must not be started with a sudden impulse. Its inertia will resist and something must give way. A gradual starting can be obtained by the slipping of the belt at first, but this is expensive. The best plan is to conduct the power through a species of friction clutch--an iron disk between two wooden ones. This has been found to work admirably.

BRAKES.--The first centrifugals had no brakes. They ran until the friction of the bearings was sufficient to stop them. This occasioned, however, rapid wearing and too great a loss of time. The best material for a brake consists of soft wood into which shoe pegs have been driven, and which is thoroughly saturated with oil. The wooden disks referred to just above are of the same construction. The center of oscillation ought to be in the central plane of the brake as well as that of the pulley, but the preference is given to the pulley.

Figs. 15 and 16 (I) give sectional views of a brake for hanging machines. Figs. 19, 20, and 21 give two sections and a view of a brake which can be used on both hanging and standing machines. A very simple form of brake is shown in Figs. 24, 26, and 27 (A), a mere block pressing on the rim of the basket.

OIL AND FAT.--A machine in most respects like a whizzer is used for the "extraction of oil and fat and oily and fatty matters from woolen yarns and fabrics, and such other fibrous material or mixtures of materials as are from their nature affected in color or quality when hydrocarbons are used for the purpose of extracting such oily or fatty matters, and are subsequently removed from the material under treatment by the slow process of admitting steam, or using other means of raising the temperature to the respective boiling points of such hydrocarbons, and so driving them off by evaporation." In the centrifugal method carbon-bisulphide, or some other volatile agent, is admitted and is driven through the material by centrifugal force, when the necessary reactions take place, and is allowed to escape in the form of hydrocarbons. A machine differing only in slight particulars from the above is used for cleansing wool.

LOOSE FIBER.--Another application is the drying of loose fiber. Two distinctive points deserve to be noticed in the centrifugal used for this purpose. An endless chain or belt provided with blades moves the material vertically in the basket, and discharges it over the edge. During its upward course the material is subjected to a shower of water to wash it.

OIL FROM METAL CHIPS.--Very material savings are made in many factories by collecting the metal chips and turnings, coated and mixed with oil, which fall from the various machines, and extracting the oil centrifugally. The separator consists of a chip holder, having an imperforate shell flaring upward and outward from the spindle (in fixed bearings) to which it is attached. When filled, a cover is placed upon it and keyed to the spindle. Between the cover and holder there is a small annular opening through which oil, but not chips, can escape. Fig. 29 (Pat. 225,949--C.F. Roper) is designed (like the greater part of the drawings inserted) to show relative position of parts merely, and not relative _size_. This style of machine can be used for sugar separating (Pat. 345,994--F.P. Sherman) and many other purposes, to which, however, there are other styles more especially adapted.

FILTERERS.--There are two distinct kinds of centrifugal filterers, working on different principles. Petroleum separators (Pat. 217,063) are of the first kind. They are in form in all respects like a sugar machine. The flakes of paraffine, stearine, etc., which are to be extracted, when chilled are very brittle and would be disintegrated upon being hurled against a plain wire gauze and would escape. Even a woven fabric presents too harsh a surface. It is necessary to have a very elastic basket lining of wool, cotton, or other fibrous material. The basket itself may be either wire or perforated, but must have a perfectly smooth bottom.

As the pressure of the liquor upon the filtering medium per unit of surface depends entirely upon its radial depth, mere tubes, connecting a central inlet with an annular compartment, will serve the purpose quite as well as a whole basket. In this style of machine (Pat. 10,457) the filtering material constitutes a wall between two annular compartments. The outer one is connected with a vacuum apparatus.

Filterers of the second kind work on the following principle: If a cylinder be rapidly revolved in a liquid in which solid particles are suspended, the liquid will be drawn into a like rotation and the heavy particles will be thrown to the outer part of the receptacle. If a perforated cylinder is used as stirrer, the purified liquid will escape into it through the perforations and may be conducted away. The impurities, likewise, after falling down the sides of the receptacle, are carried off. The advantages of this method are that no filtering material is needed and the filtering surface is never in contact with anything but pure liquor.

Very fine sawdust is, to a considerable extent, employed in sugar refineries as a filtering medium. By such use the sawdust becomes mixed with sand, fine particles of cane, etc. As sawdust of such fineness is expensive, it is desirable to purify it in order to reuse it. A centrifugal (Pat. 353,775--J.V.V. Booraem) built on the following principle is used for this purpose. It has been observed that by rotating rather _slowly_ small particles of various substances in water, the finer particles will be thrown outward and deposit near the circumference of the vessel, while the heavier and coarser particles will deposit nearer to or at the center, their centrifugal force not being sufficient to carry them out. A mere rod, extending radially in both directions, serves by its rotation to set the water in motion.

Another form of filter of this second kind (Pat. 148,513) has a rotating imperforate basket into which the impure liquor is run. Within and concentric with it is another cylinder whose walls are of some filtering medium. The liquid already partly purified by centrifugal force passes through into the inner cylinder, thus becoming further purified. Centrifugal filters are used also to cleanse gums for varnishes.