8 ANEMOMETER & ANEMOSCOPE Anemometro ed Anemoscopio
9 IGROMETER Igrometro
This anemometer measures the force of the wind using a lamina (thin metal plate) hinged at the top and left free to incline at the bottom; the lamina deviates more or less from its vertical resting position according to the intensity of the wind. The lamina moves like a pointer on the quadrant shaped structure which bears a graduated scale. This instrument, called “lamellae anemometer” or “windbrush”, is part of the equipment devised by Leonardo in his preliminary studies for mechanical flight. This kind of apparatus is intended to supply the necessary information on atmospheric conditions, particularly on the ever-varying aspects of air and winds. Leonardo also refers to the possibility of measuring the velocity of the wind using a clock together with the anemometer: “Here you need a clock showing hours, points and minutes”. Such an instrument is completed by the anemoscope whose indispensable function is to show immediately the direction in which the wind is blowing. It is a very simple device, it works like the common weather-vane fixed on top of a building but it has more degrees of freedom (both on the horizontal and vertical axis), as it is placed on a pivot pin that allows it to bend in all directions.
A Michele Lombardi and CEA Exibition
31