Quintant used by William Napier during the Peninsular War

A quintant was a navigational instrument like a sextant. A quintant's dial was formed from an arc of one fifth of a circle, whereas a sextant's arc was one sixth.

Major-General Sir William Napier served with great distinction in the Peninsular War (1808-1814), taking part in many of the major actions of that campaign including Fuentes d'Orno, the storming of Badajoz, Salamanca and Nivelle. He later wrote a six volume 'History of the War in the Peninsula' (1828-1840) that was published to great acclaim.