Aeroklinoscope

Aeroklinoscope is the name of an instrument invented by Buys-Ballot, and used in connection with weather-signals for exhibiting publicly the difference of barometric pressure at different observing stations. One form is a pole 30 feet high, turning on a pivot, and having on the top a horizontal arm capable of being inclined more or less. The system of working the arm is settled by agreement. See SIGNALLING.