This is a sensitive anemometer by CF Casella. With the aid of a stop watch the wind speed over a given period can be calculated. This model is circa 1965 & is in working condition. More information is shown on the extract from Casella’s sales book dated 1963.
Good condition. However, there is a stress fracture to the rear of the case, but this does not affect the working – note, the instrument is designed not to be left outside permanently.
Casella Anemometer – Sensitive Pattern c. 1965 England