... some colored, gave the pleasing impression of a floating city on the bosom of the great deep; and so it was. Very soon there was brisk signaling, with blazing torches, between the Ben Deford and the Malvern ; and, at eight o'clock, General Butler departed for the latter in his gig to confer with Admiral Porter. On his return, he announced that it was intended to explode the floating mine, near Fort Fi...