It might be supposed that in the construction of so many subterranean ways, in such different sections of the continent, almost every conceivable geological formation must have been traversed; and so it appears from Mr. Storrow's report. Granite, quartz, oolite, limestone, shale, slate, sandstone, gravel, sand, clay and marl, were the material through which with pick and spade, drill and shovel, the patient workmen made their way. Not unfrequently, more than half the varieties of rock and earth we have named were met with in the same tunnel. Sometimes the work would be interrupted and temporarily abandoned in consequence of an inundation of water; sometimes enormous masses of gravel and sand would work through into a shaft or tunnel, with disastrous and, in two instances, with fatal consequences. In many instances, work was discontinued for years, for want of funds, and then afterward renewed, with eventual success. In fact, about the average amount of those ordinary and inevitable obstacles which stand in the way of all great enterprises, were encountered by the engineers and contractors, in the building of these tunnels; but time, money, and skill, never failed to remove every difficulty. But we propose to extract, and condense from Mr. Storrow's report, a few of the main facts about some of the most important of these works; as the report has, not been read, or even seen by one in a hundred. The "Box Tunnel" between Chippenham and Bath is more than a mile and three quarters in length. Nearly one half its length passes through a kind of limestone rock, and the other through clay, the clay end being lined with masonry. Five shafts were sunk, the deepest being about three hundred feet. "During the construction of this tunnel, great difficulties were encountered from the excessive quantity of water which inundated the works, sometimes even occasioning their partial suspension, and powerful means were required to overcome the obstacles. At one time the water fairly got the mastery over the machinery used for its removal, and it was only after an additional set of pumps worked by a fifty horse power engine, that the work could be resumed." This tunnel was built in five years, and its cost was about $1,750,000, or about $547 a yard.