A correspondent of the New York Daily Times, with a sagacity which is quite surprising, proposes that the Leviathan be filled with coal gas, which, he says, will take away half her weight, and she may then be launched with ease. We have no doubt that Mr. Brunei will feel very grateful for this suggestion, but we scarcely think that he will have any occasion to aot upon it, as we expect from the accounts received by the Canada, that she is now floating in her proper element.