- amazing inclinometer fact -
This instrument was used for controlling the air position of the flying machines devised by Leonardo. For the machine to reach the horizontal position indispensable for certain flight conditions, the small ball in the bell jar must be positioned right in the middle of the inclinometer. The bell glass is for preventing the wind from affecting the ball.
Codex Atlanticus, folio 1058 former folio 381 r.a.
Drawing extracted from the book, Il Codice Atlantico di Leonardo da Vinci nella biblioteca Ambrosiana di Milano (Editore Milano Hoepli 1894-1904.)
The original Leonardo drawing is kept in the Biblioteca Ambrosiana
The upper portion of the folio shows drawings to do with weights applied to scales, and experiments for measuring the robustness of screws. In the lower portion is a drawing of the inclinometer, which can be dated between 1483 and 1486. Next to this instrument - devised for measuring verticality and used for flying - there is the caption, non ci vuol dare il vento "there has to be no wind" and also Questa palla dentro al cerchio ha esser quella che ti farà guidare lo strumento diritto o torto, come vorrai, cioè quando vorrai andare pari, fa che la palla stia nel mezzo del cerchio, e la pruova te lo insegnerà "The ball in the middle of the circle will enable you to direct the course of your machine. That is, whenever you want to fly horizontally make sure the ball is in the middle of the circle. Give it a try and you'll see".