It was not till the year 1844, more than ten years after he began to experiment, and more than five years after discovering the secret of vulcanization, that he was able to conduct his process with absolute certainty, and to produce vulcanized India-rubber with the requisite expedition and economy.  We can form some conception of the difficulties overcome by the fact, that the advances of Mr. De Forrest in aid of the experiment reached the sum of forty-six thousand dollars,—­an amount the inventor did not live long enough to repay.

His triumph had been long deferred, and we have seen in part how much it had cost him.  But his success proved to be richly worth its cost.  He had added to the arts, not a new material merely, but a new class of materials, applicable to a thousand diverse uses.  His product had more than the elasticity of India-rubber, while it was divested of all those properties which had lessened its utility.  It was still India-rubber, but its surfaces would not adhere, nor would it harden at any degree of cold, nor soften at any degree of heat.  It was a cloth impervious to water.  It was paper that would not tear.  It was parchment that would not crease.  It was leather which neither rain nor sun would injure.  It was ebony that could be run into a mould.  It was ivory that could be worked like wax.  It was wood that never cracked, shrunk, nor decayed.  It was metal, “elastic metal,” as Daniel Webster termed it, that could be wound round the finger or tied into a knot, and which preserved its elasticity almost like steel.  Trifling variations in the ingredients, in the proportions, and in the heating, made it either as pliable as kid, tougher than ox-hide, as elastic as whalebone, or as rigid as flint.

All this is stated in a moment, but each of these variations in the material, as well as every article made from them, cost this indefatigable man days, weeks, months, or years of experiment.  It cost him, for example, several years of most expensive trial to obviate the objection to India-rubber fabrics caused by the liability of the gum to peel from the cloth.  He tried every known textile fabric, and every conceivable process before arriving at the simple expedient of mixing fibre with the gum, by which, at length, the perfect India-rubber cloth was produced.  This invention he considered only second in value to the discovery of vulcanization.  The India-rubber shoe, as we now have it, is an admirable article,—­light, strong, elegant in shape, with a fibrous sole that does not readily wear, cut, or slip.  As the shoe is made and joined before vulcanization, a girl can make twenty-five pairs in a day.  They are cut from the soft sheets of gum and joined by a slight pressure of the hand.  But almost every step of this process, now so simple and easy, was patiently elaborated by Charles Goodyear.  A million and a half of pairs per annum is now the average number made in the United States by his process, though the business languishes somewhat from the high price of the raw materials.  The gum, which, when Goodyear began his experiments, was a drug at five cents a pound, has recently been sold at one dollar and twenty cents a pound, with all its impurities.  Even at this high price the annual import ranges at from four to five millions of pounds.