The Rhine may, perhaps, fairly be compared with the Upper Danube, between Lintz and Vienna, even between Vienna and Pesth. There is no great disparity so far, either in the size of themselves or of the hills and plains through which they run. The traveller’s tastes, artistic and historical, decide his preference. The constant succession of ruined holds of the old oppressors of the earth which he meets on the Rhine, are wanting on the Danube. It is certainly a satisfaction to see such places thoroughly ruined--to triumph over departed scoundrelism wherever one comes on its relics. As a compensation, however, he will find on the Danube a huge building or two, such as that of the Benedictine Monastery at Molk, or the Cathedral and Palace of the Primate of Hungary at Gran, of living interest, and with work still to do in the world. There is not much to choose between the banks of the two streams in the matter of general historical interest, though to me the long struggle between the Christian and the Moslem, the footprints of which meet one on all sides, gives the Danube slightly the advantage even in this respect. There are longer gaps of flat uninteresting country on the eastern stream, no doubt, which may be set off against the sameness and neatness of the perpetual vineyard on the western; and on the Danube you get, now and then, a piece of real forest, which you never see, so far as I remember, on the Rhine. Below Belgrade, however, all comparison ceases. The Rhine is half the size of its rival, and flows westward through the highest cultivation and civilisation to the German Ocean, while the huge Danube rushes through the Carpathians into a new world--an eastern people, living amidst strange beasts and birds, in a country which is pretty much as Trajan left it. You might as well compare Killiecrankie to the Brenner Pass, as any thing on the Rhine to the Kazan, the defile by which the Danube struggles through the western Carpathians. Here the river contracts in breadth from more than a mile to between 200 and 300 yards; the depth is 170 feet. The limestone rocks on both sides rise to near 2000 feet, coming sheer down to the water in many places, clothed with forest wherever there is hold for roots. Along the Servian side, on the face of the precipice, a few feet above the stream, run the long line of sockets in which the beams were fastened for the support of his covered road by Trajan’s legions. A tablet and an inscription 1740 years old still bear, I believe, the great Roman’s name, and a memorial of his Dacian campaign, though I cannot vouch for the fact, as we shot by it at twenty miles an hour; but I could distinctly see Roman letters. On the left bank the Austrians have carried a road by blasting and masonry; and a cavern which was held for weeks by 400 men against a Turkish army in 1692 commands the whole pass.