Psychrometer

Psychrometer in glass thermometers of Prismatic capillary range: +20 °F to 120° F or -5°C to 50°C mounted side by side in a wooden frame which is provided with a handle and spindle, so that the frame with thermometers can be rotated quickly about a horizontal axis. The bulb of one of the thermometer is - covered by a closely fitting cylindrical cotton wick, the end of which dips in small water container attached to the end of the frame.