79

Steam Navigation.

twenty was his constant average. The fuel, inmost places, was wood ; at Pittsburgh , and on theOhio river, it was coal and wood ; at Pittsburgh ,and at Laceling, and at a hundred other places,there was a solid mass of coal fifty miles square.They drove a shaft horizontally into the hill, andthe coals were abundant above their head fin themountains, as fine coal as any in the world. Itwas delivered at the houses of the inhabitants atsixteen bushels per dollar.—The number of steam-boats was rapidly increasing upon both the lowand high pressure system, because they had dif-ferent interests and different companies. Mr.Evans being a patentee, they had to give some-thing for the use of his patent; if they could notmake their bargain with him, they used the low-pressure engine; but there was a new engine,built for one-third of the money, coming into usein several of the steam-boats, invented in Ame­ rica , a perfect rotatory engine; and it was sup-posed that it would supersede all other engines.—Knew of no other guard than that of properlyconstructing the safety valves, and the manner ofloading them, so that they coukl not get on morethan a certain weight; they must of course con-struct them strong enough, and prove them.They were under no Government regulations.—It was supposed that a rotatory engine consumedless coals than one with a reciprocating beam.Twelve bushels of coals, with the rotatory motion,