The quadrant is an instrument for measuring heights. This one is made of brass. One face displays the 'Tabula Solis' which allows the entrance of the sun into the different signs of the zodiac to be derived. It also bears a shadow square, to calculate heights and make topographical measurements, and the indication of the latitude for which the instrument is calibrated, in this case 43? 40' corresponding to the city of Florence. On the back of the quadrant is the wind rose, for indicating wind direction.
The instrument is dated and signed by Giovanni Battista Giusti, an instrument maker in Florence around the 1560s, probably in the Medici metal workshop.