Gunner's sights and levels are found either separately or combined together in composite instruments. They were intended to be set up on the barrels of large guns so that gunners could aim at their target and elevate the gun to the correct angle for the estimated range.
As with other artillery instruments, sights and levels were introduced in the 16th century. They were intended to accompany the new form of cast bronze guns which came into increasing use from the late 15th century. This new style of artillery could be set at variable elevation: pivoting around its trunnions, the gun could be placed at an angle determined by the master gunner.
To achieve maximum destructive force, most cannon were in practice fired at point blank range, for which the gun remained horizontal. But after Niccolo Tartaglia's La nova scientia (1537) - the first published work on the 'new science' of artillery and ballistics - there was much discussion of the increased range that could be obtained by elevating the gun.
