This can measure both horizontal and vertical angles and is mounted on a swivel joint. The moveable arm can stretch to join the other arm. The round part of this instrument has engravings marking the winds: 'Tramontana' (North), 'Ostro' (South), 'Greco' (NE wind), 'Garbino', 'Levante' (East), 'Ponente' (West), 'Scirocco (SE wind)', 'Maestro' (North west), 'Anovoli'. On the underside of the round part is engraved 'Piombo', 'Ferro' and 'Pietro' meaning lead, iron, and stone.