ays of
improvement, anything whatever could be considered finished. At
present, all engines are provided with these joints and valves, which
save steam, diminish jar, and facilitate the separation of the parts.
It is difficult to compute the value of this improvement, in money. We
are informed, however, by competent authority, that a steamer of two
thousand tons saves ten thousand dollars a year by its use. Such is
the demand for the engine-packing, as it is termed, that the owners of
the factory where it is chiefly made, after constructing the largest
water-wheel in the world, found it insufficient for their growing
business, and were obliged to add to it a steam-engine of two hundred
horse-power. The New York agent of this company sells about a million
dollars' worth of packing per annum.

Belting for engines is another article for which Goodyear's compound
is superior to any other, inasmuch as the surface of the India-rubber
clings to the iron wheel better than leather or fabric. Leather
polishes and slips; India-rubber does not polish, and holds to the
iron so firmly as to save a large percentage of power. It is no small
advantage merely to save leather for other uses, since leather is an
article of which the supply is strictly limited. It is not uncommon
for India-rubber belts to be furnished, which, if made of leather,
would require more than a hundred hides. Emery-wheels of this material
have been recently introduced. They were formerly made of wood coated
with emery, which soon wore off. In the new manufacture, the emery is
kneaded into the entire mass of the wheel, which can be worn down till
it is all consumed. On the same principle the instruments used to
sharpen scythes are also made. Of late we hear excellent accounts of
India-rubber as a basis for artificial teeth. It is said to be
lighter, more agreeable, less expensive, than gold or platina, and not
less durable. We have seen also some very pretty watch-cases of this
material, elegantly inlaid with gold.

It thus appears, that the result of Mr. Goodyear's long and painful
struggles was the production of a material which now ranks with the
leading compounds of commerce and manufacture, such as glass, brass,
steel, paper, porcelain, paint. Considering its peculiar and varied
utility, it is perhaps inferior in value only to paper, steel, and
glass. We see, also, that the use of the new compound lessens the
consumption of several commodities, such as ivory