would be able to stow 400 tons of coal. To supply a 10 horse-power, daily required an expenditure of a ton of coals, and, consequently, 200 horse-power would require 20 tons of coal daily; but if the vessel carried 400 tons of coal only, it would not be practicable to undertake a voyage which would require the whole of that quantity. They must make an allowance of 100 tons for contingencies. Thus, in reckoning the average length of the voyage which might be undertaken by such a vessel, we might safely calculate upon 300 tons of coal, which would be sufficient for fifteen days, and it might fairly be concluded that any project which calculated upon making longer voyages than fifteen days without taking in a fresh supply of coals, in the present state of the steamboat, must be considered chimerical. Now, the average rate of speed of the Mediterranean packets was 170 miles per day, and the utmost limit of a steam voyage might be taken at 2550 miles; but even that could not be reckoned upon.” It is, however, fair to the scientific memory of Dr. Lardner to state that, in the eighth and last edition of his “Steam-engine, Railways,” &c., 1851, pp. 294-309, he declares that he never stated that a “steam voyage across the Atlantic was _a physical impossibility_:” the more so, that he was of course well aware of the previous voyages of the _Savannah_ and _Curaçoa_; what he did say (especially at the meeting of the British Association at _Bristol in 1836_) was “that the long sea voyages which were contemplated could not be maintained with that regularity and certainty which are indispensable to commercial success by _any revenue which could be expected from traffic alone_, and _that, without a government subsidy of a considerable amount_, such lines of steamers, although they might be started, could not be permanently maintained.” [168] The _Royal William_ was between 400 and 500 tons, built at Three Rivers, Canada, and her engines, constructed in England, were fitted into her at St. Mary’s Foundry, Montreal. She only made this one Atlantic passage and was subsequently sold to the Portuguese Government.