Original Retro has dated this Antique Brass Anemometer to the 1930s.
This is a unusual Velocity in Feet anemometer by Short & Mason London from around 1930

Velocity in Feet 200 - 3000 R.P.M. - Zero setting pat. No. 3729 - No. G 6938 - Made in Gt. Britain.
The Velocity Anemometer is housed in a brass and brass blackened housing and the wind propellor is situated behind the anemometer
within and large brass blackened housing.
The original correction sheet comes with the anemometer.
The anemometer comes with it's original leather and purple velvet casing
Original Retro has dated this Antique Brass Anemometer to the 1930s.
You can view the stock and full dealer information on the Original Retro Profile Page