| When the ten minutes are up, as signified by the ding of an egg timer, a piece of nautical equipment as pedigreed as an astrolabe or a sextant. |
| A compass, sextant and charts were the necessary tools for plotting a course. |
| It represents the octant, a navigational instrument that was replaced by the sextant in the latter half of the 18th century. |
| The arc was extended from an octant to a sextant and a stout handle was added at the back of the instrument. |
| The sextant, a navigational tool used to indicate latitude, was lent to the museum by a local maritime historian. |
| In the octant and the sextant, two mirrors one fixed, the other movable bring the image of the Sun into coincidence with the horizon. |
