Sometimes the construction engineer of the railroad brings his new line face to face with a mountain too steep to be easily mounted. Then he may prepare to pierce it. Tunnels are not pleasant things through which to ride. They are, moreover, expensive to construct, and when once constructed are an unending care, necessitating expensive and constant inspection. But--and that "but" in this case is a very large one--they reduce grades and distances in a wholesale fashion; and when you reduce grades you are pretty sure to be reducing operating expenses. A railroad man will think twice in his opposition to a smoky bore of a tunnel that will cost some three to five million dollars, when his expert advisers tell him that that same smoky bore will save him a hundred thousand tons of coal in the course of a year. From almost its very beginnings the American railroad has been dependent upon tunnels, and thus has closely followed European precedent. The Alleghany Portage Railroad, to which reference has already been made, passed through what is said to have been the first railroad tunnel in the United States. It pierced a spur in the Alleghany Mountains, and it was 901 feet in length, 20 feet wide, and 19 feet high within the arch, 150 feet at each end being arched with cut stone. The old tunnel, built in 1832, which has not echoed with the panting of the locomotive for more than half a century, is still to be found not far from Johnstown, Pa. It simply serves the purpose to-day of calling attention to the durable fashion in which the earliest of our railroad-builders worked.