NIAGARA FALLS AND LAKE ERIE,—Prof, Silliman, the eminent geologist, discredits the opinion advanced by some th&t information wearing away of the rocks of hard limestone may possibly result in draining take Erie. In reesnt lecture he remsikod —B They will not halt at their present thought tat point slowly aad surely about two miles torrent when they will stop again for an unknown period, and probably forever, since at this place the hard limestone will form both base and top of the falls, and thus stop the destruction of the rock. Some have thought that they would finally reach Lake Erie, and that then the lake would be completely drained, such an event is impossible. At the point already mentioned, the torrent will gradually wear away the surtacn of the limestone, forming a rapid, and thenceforth Niagara will be one ol the lost wonders ol tiie world," BED OP THK MISSISSIPPI.—The "Alton Telegraph ;) says, it lias generally been the received opinion of geologists that the Mississippi and tributaries traversed a valley, with a strata dipping towards the bed on each side. Recent observations prove, very conclusively, that this is all a mistake. Dr. Norwood's survey, as well as the excavation of the artesian well at Belcher's refinery, at St. Louis, show that the line ol the Mississippi traverses a ridge, and not a valley, iind thai tb" strata dips trom the river east ami west. In other words, that the bed ol the Mississippi trover- I ses a line of anti-dimii axis or upheavals.--This theory is applied by Mr. Phillips, to explain the structure of lead veins in the West. LOCOMOTIVE BUILDING.—The business of building locomotive engines has become an important branch of domestic industry, and is steadily growing in magnitude. According to an estimate made by the " Railroad Journal," there are probably no less than one thousand locomotives built yearly by the shops now in operation, sufficient to stock frorn three to four thousand miles of road. From ten to fifteen thousand tons of cast-iron, and the same amount of wrought-iron, and a large amount of other stock ara used by these establishments for this yearly production.