Rubber

“ The earliest experiment in cultivating rubber was made only as far back as the seventies of last century. And it is only within the present century that cultivated rubber, or, as it is more generally called, “plantation rubber,” has become a power in the industrial world. ”

“ It should be remembered, however, that no rubber can be made strong enough to be absolutely proof against tearing or puncturing by extremely sharp edges, such as stiff stubble, sharp-edged rocks, broken glass, etc. ”

“ It is on rubber that infants cut their teeth; after all the teeth are gone old age makes use of rubber in plates for false teeth. Ten million motorists and other millions of cyclists in the United States ride on rubber tires that are durable, noiseless and airtight. Balloons of rubber float aloft, and huge submarines plow their routes beneath the ocean's surface propelled by electricity stored in great rubber cells. Sheathed in rubber, the lightning makes a peaceful way through our homes, offices and factories, furnishing light and telephone service. ”

“ India rubber can be so readily shaped in moulds and the latter are so readily made of plaster of paris that any one who is interested in such things will find endless amusement in working out different designs. ”

“ If the timber is too green, steam is formed as well as smoke, and the sheets of rubber may have a moist surface glaze.
Sun-Drying Sheet Rubber.—Among the first curious sights which impress the visitor or newcomer to this country is the spectacle of sheet rubber hanging in the sun on native holdings. From what one has learned of the extraordinary [148] care which must be exercised in all the processes of rubber preparation, one fails to understand how such rubber reaches the market without becoming tacky. ”

“ In spite of the wonders which rubber has already accomplished, and the adventures, which have colored its history, only the beginning of the romance of rubber has been told. The plantation industry is still in its infancy, and experiments are constantly being made to determine the best methods of planting, the most fruitful number of trees to the acre, the most advantageous way of tapping. In the laboratories of the great rubber manufacturers, scientists are at work improving old methods of using rubber and devising new ones. ”

“ And rubber makes a belt around the world in its natural as well as in its manufactured form. The rubber-bearing zone winds north and south of the equator through both hemispheres. In South America rubber is the latex of certain trees, in Africa of trees and vines. The best "wild" rubber still comes from Para in Brazil. It is gathered and prepared for shipment there today by the same methods the natives used four hundred years ago. The natives in their canoes follow the watercourses into the jungles. ”

“ Rubber air-brake hose on railroad trains makes safe the travel of a nation, air-drill hose rivets our ships, fire hose protects the properly in city and town and garden hose brings nourishment to our growing plants. Rubber clothing protects against storm and rubber footwear guards us against cold and wet. Tennis balls and golf balls and rubber-cored baseballs give healthful sport to the millions. In hospitals and medical work the uses of rubber are without number. ”

“ Out oozes a thickish white substance, some of which drops on to your fingers. Without a moment’s thought or hesitation, it comes natural to you to rub thumb against sticky fingers, whereupon the substance gradually solidifies, and at last breaks loose in the form of a tiny pellet. In a similarly simple way the mere savage discovered rubber hundreds of years ago ”

“ The rubbers are heavier than the pacs and more protection to tender feet, but are more likely to tire the wearer, especially since rubber clings so fondly to all brush and weeds with which it comes in contact. ”

“ Sheet rubber is made from the blocks of masticated gum by slicing. A machine is used for the purpose which carries a knife which works back and forth in the direction of its length at high speed, making two thousand cuts a minute. ”

“ The sheets of rubber, after being dried, are taken to the “compound” room, where they are sprinkled with whiting, to prevent sticking, and weighed. Next they are taken into the calender room to a “mixer,” by [235] means of which the rubber is combined with other substances, which include sulphur, litharge, whiting, lampblack, tar, resin, lime, palm oil, and linseed oil. ”

“ To obviate this disadvantage is the object of my invention, which consists in forming the packing with a backing of pure vulcanized rubber, or rubber of sufficient elasticity for the purpose desired, which may be covered and protected by a strip of canvas or other suitable fabric. In the drawing, a represents the ordinary packing-band which is backed by the rubber strip, b, the whole being vulcanized together, so as to be solidly united; and the rubber may be covered, if desired, by the canvas strip, c, to protect it from injury. ”

“ Nor are we impressed with the argument that, being rubber itself, it must be regarded as a material, and not an article composed of rubber, for its adaptation to dental purposes has differentiated it commercially. Washing and scouring wool do not make the resulting wool a manufacture of wool; cleaning and ginning cotton do not make the resulting cotton a manufacture of cotton; but sulphur and coloring matter, when applied as here, make the resulting rubber, while still remaining rubber, an article of rubber, as contradistinguished from rubber crude, or rubber merely cleansed of impurities. ”

“ One or two evenings I go to the upper part of the wood to cut some fern-pegs for pegging Carnation layers, armed with fag-hook and knife and rubber, and a low rush-bottomed stool to sit on. The rubber is the stone for sharpening the knife—a long stone of coarse sandstone grit, such as is used for scythes. Whenever I am at work with a knife there is sure to be a rubber not far off, for a blunt knife I cannot endure, so there is a stone in each department of the garden sheds, and a whole series in the workshop, and one or two to spare to take on outside jobs. ”

“ For improvement in the manufacture of India-rubber. We here disclaim the use of rubber and sulphur alone, as also the submitting of rubber, or rubber compounds to a high degree of heat, patents having been granted for that process, in this and other countries; neither do we wish to secure the right of coloring rubber, such having frequently been done by rubber manufacturers. ”

“ It will pay you to take some trouble to protect the rubber strands as far as possible. Lay them away in a can or jar in some cool, dry and dark place when they are not in use. Some boys cover the rubber with powdered chalk. When the surface of the rubber begins to granulate, its best days are over. Rubber is originally white in color, while the refining process gives it the familiar gray tone. ”

“ With regard to the method of collecting rubber by scraping a hole in the earth, and leaving the sap which trickled down into it to be dried by the natural heat of the earth and the air, I can only assure you that the white man found the aborigines “making” raw rubber in this way, so they must have invented the plan themselves. ”

“ The manipulation of pure sheet rubber is simple, yet is liable to lead to disappointment. When two pieces are laid face to face and cut across with a sharp knife, or scissors, the edges will adhere with considerable tenacity. This may be increased by applying some thick solution of india rubber in a volatile solvent, and by manipulating the sheets so as to bring the entire surfaces of the cuts together. ”

“ Rubbers for large surfaces 23are usually made of soft old flannel, firmly and compactly put together somewhat in the form of a ball, and the more they possess softness and compactness, and are large and solid, the more quickly and satisfactorily will they polish extensive surfaces. Small pliable rubbers are usually employed for chairs or light frame-work. Perhaps for a beginner a rubber made of old flannel may be best, as it takes some little practice to obtain the necessary lightness of hand. ”

“ Rubber is a substance of so many important characteristics that its uses are countless. It is used for certain purposes because it stretches, for others because it is airtight and watertight, for others because it is a non-conductor of electricity, for others because it is shock-absorbing, and for others because it is adhesive. ”

“ According to the use to which rubber is to be put, it has to be mixed with certain other materials, to make a material that is neither too heavy nor too light, too hard nor too soft, too tough nor too elastic, to fulfil its purpose. And according to the price at which the goods are to be sold, certain other materials must be mixed with the rubber. It is with regard to the proportions in which such mixings are made that the manufacturers have secrets of their own which they specially want to guard. ”

“ Block rubber is considered to possess certain advantages in securing a constant proportion of water, and in being satisfactory for transport. The best condition and form in which to export rubber cannot be regarded as settled. The probabilities are that in the end the production of a rubber as nearly as possible free from water and impurities and of constant composition will be realized as best meeting the requirements of the modern manufacturer. ”

“ By removing the press from time to time and inspecting the overflow of india rubber the progress of the operation can be watched. An extra piece of india rubber may be placed on a piece of wood by the side of or upon the wooden portion of the press, and its condition can be taken as the criterion. Pressure with the point of a knife will tell the vulcanizing point. ”

“ Air goods, such as cushions, beds, gas bags, and so forth, are made of textile fabrics which have been coated with mixed rubber either by the spreading process above described, or by means of heated rollers, the curing being then effected by steam heat. The manufacture of overshoes and fishing boots is an analogous process, only the canvas base is more thickly coated with a highly pigmented rubber of low quality. ”

“ On the other hand, rubber seems to cling to the ground, no matter how much it is worn. The only objection to rubbers is that they are uncomfortably warm in hot weather; but that difficulty can be overcome by frequently plunging into a cool stream and standing there for several minutes. ”

“ In the house there are rubber washers on the taps, rubber rings on the stoppers of the ginger-beer bottles within the pantry, a teapot on the kitchen dresser has been mended with a rubber spout, and the children are playing with rubber balls, dolls, and toy balloons. ”

“ It is a cheerful sight to see the workers, men and women, dressed in all the colors of the rainbow, trooping out from their quarters to begin the day's work. The tapping must be done early in the day, for the latex or rubber juice stops flowing a few hours after sunrise. ”

“ The word elastic, in physics, is the name given to the tendency which a body exerts, when distorted, to return to its original shape. Rubber possesses more elasticity than any other material known, it being possible to stretch a piece of rubber cord to eight or nine times its original length without fracture. Rubber also possesses the added requisite of lightness and will store up more energy than any form of steel spring. ”

“ An equally fascinating story might be told of its progress through the factory, how it is kneaded and rolled, mixed with chemicals, rubbed into fabrics, baked in ovens, and finally emerges as any one of the tens of thousands of articles that are made wholly or partly from rubber. ”

“ There are grounds for believing that raw rubber is superior in some respects to fully vulcanised rubber, if prepared without the addition of finely divided mineral substances which exert a toughening effect. ”

“ A plunger that nearly fits the small end is provided. The india rubber is placed in the mould and heated. When soft, the plunger is forced down to the proper distance in the press and the article is cured. Care must be taken to give the plunger a good coating of talc, and it must be made to sit vertically. ”

“ No matter how much synthetic rubber may be manufactured or how many rubber trees are set out there is no danger of glutting the market, for as the price falls the uses of rubber become more numerous. One can think of a thousand ways in which rubber could be used if it were only cheap enough. ”

“ A high and uniform tension of the rubber warp is so important that most manufacturers keep men specially employed in the testing of the threads, instead of leaving this matter to the weavers. These testers acquire such a keen sense of touch that they can obtain very economical and satisfactory results. ”

“ It is difficult to fully realize how many comforts and conveniences we derive from rubber and not the least among them is the multiplicity of woven fabrics which are used both for comfort and convenience in a variety of ways and for innumerable purposes. ”

“ It must be recognised also that the machines are liable to considerable damage if extraneous substances are allowed to enter—for example, tapping-knives, stones, pieces of iron, spouts, etc., which are sometimes present in the loose scraps of rubber or shavings, owing to the carelessness of coolies. ”

“ When ordinary vulcanized rubber is heated to 230° Centigrade, (446° F.) or until it melts, a permanently viscous product is obtained, and this substance, if mixed with emery and sulphur to a kind of paste, forms a material out of which the so-called agglomerated emery wheels or grinders may be140 formed, the mixed materials being next hardened or cured by the application of a steam heat. ”

“ A piece of rubber cloth is gored to fit around the body, and is tacked to each side piece, a rubber cord fastened to each strip, and running around the front of the well, serving to keep it down, and the after ends being tucked in between the backboard and the body, all falling off in an upset. ”