We quitted Coblentz at ten, and now began in truth to enter the fine scenery of the Rhine. The mountains, or rather hills, for they scarcely deserve the former name, close upon the river, a short distance below the town, and from that moment, with very immaterial exceptions, the road follows the windings of the stream, keeping generally within a few yards of the water. The departures from this rule are not more than sufficient to break the monotony of a perfectly uniform scene. I have nothing new to tell you of the ruined castles--the villages and towns that crowd the narrow strand--the even and well-kept roads--the vine-covered hills--and the beautiful sinuosities of this great artery of Europe. To write any thing new or interesting of this well-beaten path, one must linger days among the ruins, explore the valleys, and dive into the local traditions. We enjoyed the passage, as a matter of course, but it was little varied, until we drew near the frontier of Prussia, when a castle, that stood beetling on a crag, immediately above the road, caught my eye. The building, unlike most of its sister edifices, appeared to be in good order; smoke actually arose from a beacon-grate that thrust itself out from an advanced tower, which was nearly in a perpendicular line above us, and the glazed windows and other appliances denoted a perfect and actual residence. As usual, the postilion was questioned. I understood him to say that the place was called the Ritterstein, but the name is of little moment. It was a castle of the middle ages, a real hold of the Rhine, which had been purchased by a brother of the King of Prussia, who is now the governor of the Rhenish provinces. This prince had caused the building to be restored, rigidly adhering to the ancient style of architecture, and to be furnished according to the usages of the middle ages, and baronial comfort; what was more, if the prince were not in his hold, as probably would prove not to be the case, strangers were permitted to visit it! Here was an unexpected pleasure, and we hastened to alight, admiring the governor of Rhenish provinces, his taste, and his liberality, with all our hearts. If you remember the satisfaction with which we visited the little hunting-tower of the poor Prince de Condé in 1827, a building whose chief merit was its outward form and the fact that it had been built by the Queen Blanche, you can form some notion of the zeal with which we toiled up the steep ascent, on the present occasion. The path was good, tasteful, and sinuous; but the buildings stood on crags that were almost perpendicular on three of their sides, and at an elevation of near, or perhaps quite, two hundred feet above the road.