-40%

Biram’s Anemometer circa 1890, Exc. Condition in Wood Box

$ 105.6

Availability: 100 in stock
  • All returns accepted: ReturnsNotAccepted

    Description

    Excellent condition brass
    Biram’s Anemometer
    Se
    ems to be in good working condition, measures about 6 inches across.
    Postage is .00 if within the US, more  If you are outside the US; no charge for careful packing.
    Biram’s Anemometer
    Mechanical anemometers are an instrument used to determine the volume of air entering or exiting mine workings. They were invented by Benjamin Biram, house steward to the Earl Fitzwilliam, owner of numerous collieries in South Yorkshire, England, in 1844.
    The formula used most often in mine ventilation using an anemometer was q=av, in which q equals the number of feet of air per minute, a equals the area of the airway in square feet and v equals velocity of air current in feet per minute. Anemometers, as used in mines, were produced in two styles, the Biram style which have the the dials and vanes on the same plane and the offset style which has the dials perpendicular to the vanes.
    Anemometers are generally collected by mining collectors and scientific instrument collectors. The earlier models do not have the capability to return-to-zero as later models do. Most have 8 vanes but range from just 4 up to 12 vanes, and have from 1 to 6 dials on the face.