Heap

David Porter, an American engineer; born in San Stefano, Turkey, Mar. 24, 1848. He graduated at West Point in 1864; served in the Civil War, with the Army of the Potomac; and is an expert, and writer on electrical engineering.; Hearing, a function of the ear. It is on the auditory nerve, situated in the temporal bone, that the sonorous undulations make their impre ion the vibrations being propagated through the surrounding medium, generally air, by the corresponding waves or undulations they produce in it. The pitch depends on the number of vibrations in a given time, the high notes being the quickest, and the low the slowest. The strength or loudne depends on the force and extent of the vibrations, The timber or quality of musical sounds, as of the flute, violin, ete., all sounding a note of the same pitch, depends on differences of form in the undulations.