From the 17th century times of rise and fall of the sun and moon were known for the different latitudes. But until the invention of the chronometer, the seaman used the glass for the intervening hours. The glass was turned every half hour which was announced on the bell with the corresponding number of strokes.

To prevent moisture of the sand, the connection between the two glass balls was sealed tight with sealing wax and secured with crossed ropes.

Catalogue: NM.7-16

Date: appr. 1800

HD: 23.5 x 12.5 cm

Signed: not signed

Origin: continental

Condition: in working condition, wear consistent with age and use