This document lists and describes various scientific instruments and their uses, including the audiometer for measuring sound intensity, bolometer for measuring infrared radiation, cryometer for measuring low temperatures, and dilatometer for measuring changes in volume. It also discusses endoscopes for examining internal body parts, fathometers for measuring ocean depths, gramophones for reproducing recorded sound, and other instruments like the hypsometer, lactometer, micrometer, nephetometer, optometer, pyrometer, rain gauge, spherometer, thermostat, viscometer, and wattmeter.