This excellent example rare six dial anemometer or high speed air meter. Most likely made by well know scientific instruments maker Negretti & Zambra from London in late 1800s early 1900s and was used to measure the velocity of the air currents in mines, tunnels and aviation laboratories. The device is made of brass and aluminium and has a nice silvered dial with six scales. On the side of the dial there is a on-and-off button. Dimensions: the diameter of the dial is 60 mm and the aluminum wind vane diameter is 70 mm and the wood case is 120 mm X 100 mm X 90 mm. The original mahogany case is in excellent condition. The anemometer is still in functioning state and has nice patina.