MY DEAR FRIEND--We have at last reached London, after a stormy passage of seven days. The accommodation in the smacks looks extremely inviting in port, and in fine weather, I doubt not, is comfortable, even at sea; but in February, and in such visitations of the powers of the air as we have endured, a balloon must be a far better vehicle than all the vessels that have been constructed for passengers since the time of Noah. In the first place, the waves of the atmosphere cannot be so dangerous as those of the ocean, being but "thin air"; and I am sure they are not so disagreeable; then the speed of the balloon is so much greater,--and it would puzzle Professor Leslie to demonstrate that its motions are more unsteady; besides, who ever heard of sea-sickness in a balloon? the consideration of which alone would, to any reasonable person actually suffering under the pains of that calamity, be deemed more than an equivalent for all the little fractional difference of danger between the two modes of travelling. I shall henceforth regard it as a fine characteristic trait of our national prudence, that, in their journies to France and Flanders, the Scottish witches always went by air on broom-sticks and benweeds, instead of venturing by water in sieves, like those of England. But the English are under the influence of a maritime genius. When we had got as far up the Thames as Gravesend, the wind and tide came against us, so that the vessel was obliged to anchor, and I availed myself of the circumstance, to induce the family to disembark and go to London by LAND; and I esteem it a fortunate circumstance that we did so, the day, for the season, being uncommonly fine. After we had taken some refreshment, I procured places in a stage-coach for my mother and sister, and, with the Doctor, mounted myself on the outside. My father's old-fashioned notions boggled a little at first to this arrangement, which he thought somewhat derogatory to his ministerial dignity; but his scruples were in the end overruled. The country in this season is, of course, seen to disadvantage, but still it exhibits beauty enough to convince us what England must be when in leaf. The old gentleman's admiration of the increasing signs of what he called civilisation, as we approached London, became quite eloquent; but the first view of the city from Blackheath (which, by the bye, is a fine common, surrounded with villas and handsome houses) overpowered his faculties, and I shall never forget the impression it made on myself. The sun was declined towards the horizon; vast masses of dark low-hung clouds were mingled with the smoky canopy, and the dome of St. Paul's, like the enormous idol of some terrible deity, throned amidst the smoke of sacrifices and magnificence, darkness, and mystery, presented altogether an object of vast sublimity. I felt touched with reverence, as if I was indeed approaching the city of THE HUMAN POWERS.