From thence I went to the cattle-show. I could see but little of that, as most of the animals were gone; but I was assured it was very fine. I believe it, if what I saw was a specimen--a pair of working oxen, perfectly white, the pair weighing 7000 pounds. In our cattle-shows at home, we find plenty of bulk, but it destroys form and symmetry: here both were preserved. The fowls are of the long-legged Spanish breed, coming to table like trussed ostriches; the plump English barndoor sort are about being introduced. I had nearly forgotten a beautiful and extraordinary invention--a rifle, not heavier than the common one, that will discharge twenty-four balls in succession without reloading. Where the ramrod is usually placed, is a smaller barrel, containing, when filled, twenty-four ball-cartridges, and, after discharging, the action of recocking introduces another cartridge, and so on, until the whole are discharged; the whole twenty-four can be discharged in as many seconds! After leaving this interesting exhibition, where I could have lingered a whole day, I was joined by a friend, an American--a gentleman of great attainments in science--to whose remarks I am indebted for the following scraps. The Merrimac, when low--as when I saw it--is a trifling stream, having a bottom of laminated rock, worn in channels by the stream. At spring and fall, there is ten or fifteen feet of depth; and to remedy this inequality, an important work was undertaken and executed: to this we bent our way. It is a canal in form, but should more properly be called a reservoir. It is 1-1/4 miles long, 100 feet wide, and 15 feet deep; of solid granite, sides and bottom--equal in durability to any work, ancient or modern. It is about half way cut through the solid granite rock, which in that part furnishes a natural wall. My friend had watched its progress, and gave me many interesting details of the engineering processes employed: among others, the tremendous application of steam and gunpowder. An engine bored holes in the rock fifteen feet deep and twelve inches in diameter; and these were so placed, and in such numbers, that at a single blast 170 tons of granite were blown into the air--an operation hardly conceivable. This canal leaves the town in a westerly direction--being, at its outset, about a quarter of a mile from the Merrimac, but gradually approximating for a quarter of a mile, until it touches and unites with that river. Between the two, is one of the prettiest of public walks, ten feet wide, having rows of trees on each side, and terminating in a point; being the end of a splendid granite wall, at its base thirty feet thick, and tapering to half the thickness, dividing the natural from the artificial stream. Here we come to a point of great interest: on the right is an artificial dam across the river, with two sharp lines at an angle of sixty-seven degrees, the point meeting the stream, thus stopping the waters, and insuring a