Inventions in the Century. Doolittle William Henry

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      The rollers operate in sets, and successive crackings are obtained by passing and repassing, if necessary, the grain through these rollers, set at different distances apart. The operation on grains of different qualities, whether hard or soft, or containing more or less of the gluten middlings, or starchy parts, and their minute and graded separation, thus are obtained with the greatest nicety.

      The Hungarians, the Germans, the Austrians, the Swiss, the English and the Americans have all invented useful forms of these rollers.

      This process was accompanied by the invention of new forms of middlings separators and purifiers, in which upward drafts of air are made to pass up through flat, graded shaking bolts, in an enclosed case, by which the bran specks and fuzz are lifted and conveyed away from the shaken material. In some countries, such as the great wheat state of Minnesota, U.S., where the wheat had before been of inferior market value owing to the poorer grade of flour obtained by the old processes, that same wheat was made to produce the most superior flour under the new processes, thus increasing the yearly value of the crops by many millions of dollars.

      Disastrous flour dust explosions in some of the great mills at Minneapolis, in 1877-78, developed the invention of dust collectors, by which the suspended particles of flour dust are withdrawn from the machinery and the mill, and the air is cleared for respiration and for the production of the finest flour, while the mill is kept closed and comfortable in cold seasons. One of the latest forms of such a collector has for its essential principle the vertical or rotatory air current, which it is claimed moves and precipitates the finest particles.

      The inventions in the class of mills have so multiplied in these latter days, that nearly every known article that needs to be cleaned and hulled, or ground, or cracked or pulverized, has its own specially designed machine. Wind and water as motive powers have been supplanted by steam and electricity. It would be impossible in one volume to describe this great variety. Knight, in his Mechanical Dictionary, gives a list under "Mills," of more than a hundred distinct machines and processes relating to grinding, hulling, crushing, pulverising and mixing products.

      Vegetable Cutters.– Modern ingenuity has not neglected those more humble devices which save the drudgery of hand work in the preparation of vegetables and roots for food for man and beasts, and for use especially when large quantities are to be prepared. Thus, we find machines armed with blades and worked by springs and a lever, for chopping, others for cutting stalks, other machines for paring and slicing, such as apple and potato parers and slicers, others for grating and pulping, others for seeding fruits, such as cherries and raisins, and an entire range of mechanisms, from those which handle delicately the tenderest pod and smallest seed, to the ponderous machines for cutting and crushing the cane in sugar making.

      Pressing and Baling.– The want of pressing loose materials and packing bulky ones, like hay, wool, cotton, hops, etc, and other coarser products, into small, compact bales and bodies, to facilitate their transportation, was immediately felt on the great increase of such products in the century.

      From this arose pressing and baling machines of a great variety, until nearly every agricultural product that can be pressed, packed or baled has its special machine for that operation. Besides those above indicated relating to agricultural products, we have cane presses, cheese presses, butter presses, cigar and tobacco presses, cork presses, and flour packers, fruit and lard presses, peat presses, sugar presses and others. Leading mechanical principles in presses are also indicated by name, as screw presses, toggle presses, beater press, revolving press, hydraulic press, rack and pinion press, and rolling pressure press and so on.

      There are the presses also that are used in compressing cotton. When it is remembered that cotton is raised in about twenty different countries, and that the cotton crop of the United States of 1897-98 was 10,897,857 bales, of about 500 lbs. each; of India, (estimated) for the same period, 2,844,000, of 400 lbs each; of China about 1,320,000, of 500 lbs each, and between two and three million bales in the other countries, it is interesting to consider how the world's production of this enormous mass of elastic fibre, amounting to seventeen or eighteen million bales, of four and five hundred pounds each, is compressed and bound.

      The screw press was the earliest form of machine used, and then came the hydraulic press. Later it has been customary to press the cotton by screw presses or small hydraulic presses at the plantation, bind it with ropes or metal bands and then transport it to some central or seaboard station where an immense establishment exists, provided with a great steam-operated press, in which the bale from the country is placed and reduced to one-fourth or one-third its size, and while under pressure new metallic bands applied, when the bale is ready for shipment. This was a gain of a remarkable amount of room on shipboard and on cars, and solved a commercial problem. But now this process, and the commercial rectangular bale, seem destined to be supplanted by roller presses set up near the plantations themselves, into which the cotton is fed directly from the gin, rolled upon itself between the rollers and compressed into round bales of greater density than the square bale, thus saving a great amount of cost in dispensing with the steam and hydraulic plants, with great additional advantages in convenience of handling and cost of transportation.

      It is so arranged also that the cotton may be rolled into clean, uniform dense layers, so that the same may be unwound at the mill and directly applied to the machines for its manufacture into fabrics, without the usual tedious and expensive preliminary operations of combing and re-rolling.

      It has also remained for the developed machine of the century to convert hay into an export commodity to distant countries by the baling process. Bale ties themselves have received great attention from inventors, and the most successful have won fortunes for their owners.

      Most ingenious machines have been devised for picking cotton in the fields, but none have yet reached that stage of perfection sufficient to supplant the human fingers.

      Fruits and Foods.– To prepare and transport fruits in their natural state to far distant points, while preserving them from decay for long times, is, in the large way demanded by the world's great appetites, altogether a success of modern invention.

      To gather the fruit without bruising by mechanical pickers, and then to place the fruit, oranges for instance, in the hands of an intelligent machine which will automatically, but delicately and effectually, wrap the same in a paper covering, and discharge them without harm, are among the recent inventive wonders. In the United States alone 67 patents had been granted up to 1895 for fruit wrapping machines.

      Inventions relating to drying and evaporating fruit, and having for their main object to preserve as much as possible the natural taste and colour of the fruit, have been numerous. Spreading the fruit in the air and letting the sun and air do the rest is now a crude process.

      These are the general types of drying and evaporating machines:

      First, those in which trays of fruit are placed upon stationary ledges within a heated chamber; second, those in which the trays are raised and lowered by mechanical means toward or farther from the source of heat as the drying progresses; third, those in which the fruit is placed in imperforate steam jacketed pans. Many improvements, of course, have been made in detail of form, in ventilation, the supplying and regulating of heat and the moving of trays.

      The hermetically sealed glass or earthenware fruit jar, the lids of which can be screwed or locked down upon a rubber band, after the jar is filled and the small remainder of air drawn out by a convenient steam heater, now used by the million, is an illustration of the many useful modern contrivances in this line.

      Sterilisation.– In preserving, the desirability of preventing disease and keeping foods in a pure state has developed in the last quarter of a century many devices by which the food is subjected to a steam heat in chambers, and, by devices operated from the outside, the cans or bottles СКАЧАТЬ