Regarding our recent Note on the periodicity of earthquakes, a reader in Peking sends us a very interesting account of what is described as the "Japan Trench." From The Realm of Nature," by Hugh Robert Mill, he culls the following extract "The Japan Trench,—In the extreme northwest the steepest part of the bounding wall of the Pacific Basin resis abruptly, barring off the sels of Japan and Okhotsk, and bearing the chain of Japanese and Kurile Islands, In front of it lies the greatest abyss in the earth's crust, the Japan Trench. It extends from 20 degrees N. to 50 N., in a crescent-shaped curve, deepening toward the steep slope of the World Ridge to the northwest, where a mighty gully, the Tuscarora Deep, 1,000 "miles Tong and 20 wide, at a depth greater than 4,000 fathoms. This deep, like most' of the oceanic trenches, is a great centre for earthquake shocks. South.
cast of the Japan Trench the floor
Text read from the printed page and cleaned; old type leaves the occasional error.