An interesting rustic early 19th century timer, consisting of an inner glass bulb filled with sand or similar enclosed in an oak wooden cage.
This timer takes approx 19 minutes 47 seconds, probably originally 20 minutes. These timers were used to measure labourers breaks and also sermon timers.
The Royal Navy also used measurer but these tended to be half hour intervals.
It measures 13.5cm h x 9.3cm w