The Progress of Invention in the Nineteenth Century.

by Edward W. Byrn

FIG. 161.—MACHINE FOR GRINDING AND WASHING CRUDE RUBBER.

Mr. Goodyear had obtained a French patent for his invention, and at the Exposition Universelle in Paris, in 1855, he fitted up at an expense of $50,000 two elegant courts with India rubber furniture, caskets and rich jewelry, and for this exhibit he had conferred upon him by the Emperor Napoleon the “Grand Medal of Honor” and the “Cross of the Legion of Honor.” It was a singular instance of the irony of fate that the decoration of the “Cross of the Legion of Honor” should have been conveyed to him while imprisoned for debt in “Clichy,” the debtors’ prison in Paris. The lofty courage of the man was well illustrated at this time in his reply to his wife’s solicitous inquiries as to how he had spent the night while in prison. He said, ““I have been through nearly every form of trial that human flesh is heir to, and I find that there is nothing in life to fear but sin.”” The declining years of his life were full of sorrow, pain and affliction, and at his death in 1860 his estate was $200,000 in debt. He lived long enough, however, to see his material applied to nearly five hundred uses, giving employment in England, France and Germany to 60,000 persons, and producing in this country alone goods worth $8,000,000 a year.

FIG. 162.—MAKING RUBBER CLOTH.

The greatest of all applications of rubber are to be found in the manufacture of boots and shoes. The number of attacks of cold, rheumatism, and death-dealing diseases from wet feet, that have been averted by the use of rubber shoes, can never be estimated, but perhaps it is safe to say that the rubber shoe has done more to conserve the health of the human family than any other single article of apparel.

In the manufacture of shoes the finest quality of rubber is received in wooden boxes 4 × 2 × 1¹⁄₂ feet, containing about 350 pounds in lumps of 1 to 75 pounds. These lumps are cut to suitable size, and are then ground and washed in the machine shown in [Fig. 161], water and steam being sprayed on the rubber during the operation. It is then worked into sheets or mats between rolls. From the grinding room the sheets are taken to the mixing room, where lampblack, sulphur and other ingredients are added, and worked into it by being passed many times between heated rolls, the sheets being finally reduced to a thickness of less than ¹⁄₃₂ of an inch. The rubber sheets are then applied to a cloth backing by cloth calendering rolls, shown in [Fig. 162], which are steam heated and by great pressure serve to incorporate the sheets of rubber and cloth into intimate and inseparable union. Out of this rubber fabric, which is made of different thicknesses for the upper, sole and heel, the patterns for the shoe are cut, and the parts are deftly fitted around the forms by girls, and secured by rubber cement, as shown in [Fig. 163]. The shoes are then covered with a coat of rubber varnish, and are put into cars and run into the vulcanizing ovens, where they remain from six to seven hours at a temperature of about 275°. The goods are then taken out, and after being inspected are boxed for the market. The vulcanizing is a very important part of the manufacture of a rubber shoe, for it is absolutely necessary in order to give them stability and wearing qualities. A shoe that had not been vulcanized would mash down, spread, become sticky and go to pieces after a few hours’ wear.

The rubber shoe industry of the United States is carried on by about fifteen large companies, representing an investment of many millions of dollars, most of which companies are located in Massachusetts, Rhode Island and Connecticut.

Some idea of the immensity of this industry may be obtained from the import statistics. In 1899 the United States alone imported crude rubber to the extent of 51,063,066 pounds, as much as 1,000,000 pounds a month coming from the single port of Para. The export of manufactured rubber goods for the same year amounted to $1,765,385. The statistics for Great Britain for 1896 showed the imports of rubber to that country to be one-third more than the imports of the United States. Germany also is a large consumer. The great Harburg-Vienna factories cover sixty-seven acres, are capitalized at 9,000,000 marks, and employ 3,500 hands. Much fine technical apparatus, toys, and balls are made here, the daily output of balls reaching 8,000. These, with the Noah’s arks of India rubber animals, are the delight of the little ones all over the world.

Although so much in evidence about us, India rubber is not by any means a cheap material. Costing only five cents a pound when Goodyear commenced his experiments, it is now worth a dollar a pound, and is therefore much more expensive than any of the ordinary metals, woods, or building materials. Many substitutes in the form of compositions of various ingredients have been devised and patented, but no real substitute for nature’s product has yet been found. For many years old and worn out rubber goods were thrown away as worthless. Now all such rubber is reclaimed, and used in many grades of goods which do not require a pure gum. Insatiable as the demands of the trade may appear, there is no need to fear a rubber famine, for the forests of trees in South America and the East Indies are practically inexhaustible, and in the rich alluvial soil of their habitat nature’s processes of growth rapidly restore the decimation.