The Keuffel & Esser Company of New York manufactured and sold this anemometer during the late 19th century. Keuffel & Esser was a large manufacturer of scientific measuring instruments starting in the middle of the 19th century and is well-represented in the collections across the museum. Anemometers measured the velocity of the air currents in mines and tunnels. Ventilation in mines kept dangerous gasses from building up and causing explosions, and anemometers could measure if the airflow was sufficient to ventilate them mine.
Engineers used anemometers to understand the interior air flow of mines. They designed complex ventilation systems with fans and interior doors to keep dangerous gases from building up and causing explosions.