We are lodged here at a very comfortable hotel, facing the Alleghany river. The town forms a triangle, situated between this river and the Monongahela, and after dinner, having arrived here early, we took a walk from the hotel, across the town, until we arrived at the latter river. The opposite bank here is of great height, and we crossed a bridge, 1500 feet long, with the magnanimous intention of going to the top of the hill to see the magnificent prospect which the summit is said to afford. But our strength, and breath, and courage failed us before we had ascended a third of the height, although there is a good carriage road up and in good condition, from the hard frost which still prevails. The view, however, even at that height, was very fine, although it was greatly marred by the smoky atmosphere which hangs over the city. After recrossing the bridge we went to the point forming the apex of the triangle, to see the confluence of the two rivers, and, as we could from there look up both rivers and down the Ohio, the view is very remarkable. The town itself disappointed us; but, perhaps, we expected more than we ought reasonably to have done from a great and dirty manufacturing town. _Harrisburgh, Nov. 18th._--We started this morning by the six o'clock train in order to see the wonderful Pennsylvania railroad by daylight. It is the great rival of the Baltimore and Ohio railway, on which we travelled with Mr. Tyson, and we were rather anxious to have an opportunity of comparing the two, which, having now seen them both, we feel competent to do. The great change which nature presents now, to what it did when the leaves were in full foliage, may make us underrate the beauties of the road we passed over to-day, but, notwithstanding this, we think there can be no doubt that the Baltimore and Ohio, taken as a whole, is by far the most picturesque and beautiful. The length of the two roads is very nearly the same; but, while the whole of the Baltimore and Ohio was beautiful, one side of the mountain being as much so as the other, the first part of the road to-day, till we reached the summit level, was very much of the same character as many other mountain regions we have passed. For many miles the road followed the course of the Conemaugh, crossing and recrossing the river, but without any very striking feature. But the moment we had passed through a tunnel, 3612 feet long, and began the descent of 2200 feet, on the eastern side of the Alleghany chain, the scene quite baffled description. The summit level of the Baltimore and Ohio is 500 feet higher; but the descent occupies a distance of seventeen miles, while the descent to-day was effected in eleven, so that, with all our partiality for the Baltimore and Ohio, it must be confessed there is nothing on it so wonderful and sublime as this. One curve was quite appalling, and it was rendered more so by the slow rate at which the train moved--not more, I should think,