Florentine cup sundial, 1580.
© Science Museum / Science & Society Picture Library
This bras sundial is the work of one of the well-known Volpaia family of Italian instrument makers and is inscribed: 'Hyeronimus Vulpariae Florentinus Faciebat AD MDLXXX'. The time is shown by the position of the shadow of the tip of the vertical style, or gnomon. There are two sets of hour-lines engraved in the cup: the broken lines numbered six to twelve and one to five show the time in normal hours am and pm, while the full, curved lines numbered nine to twenty four show the time according to the Italian system of reckoning in which the complete day-and-night period was divided into twenty four equal hours, starting from zero at sunset.