Ship’s Hand log with reel, chip and hourglass – ca. 1800
The hand log was first described in 1574 (Sharp, p 5). It consist of a wooden chip with peg, a log line, a reel and a 28 or 14 second sandglass. The chip in the shape of a circle sector and weighted with lead on the arc, is fitted with two lines to the peg. The end of the log line forms the third line. After a stray line of about thirty meters, the log line is equally divided into parts of 47 feet 3 inches (14.40 meters) to start with a flag or bunting. Thus at every 47 feet 3 inches knots are placed to denote the number of miles. The chip is thrown astern of the ship and remains static whilst the line is paid out and the ship sails away from it. The number of knots sailed out in 14 or 28 seconds indicates the speed of the ship in miles per hour or knots. Between every knot half knots are marked.
With this log a speed up to 5.5 knots can be determined. The starting point, the zero mile, is marked with a red flag and the first knot is marked with a leather vane. Half knots are indicated by simple lines without knots. The line has been repaired after a break.
The hourglass of 28 seconds is housed in a wooden house, 13 cm high. It dates from 1814.
Date: ca. 1800
LD reel: 55×24 cm (21.5×9.5 in)
Signed: not signed
Condition: in good and working condition, wear consistent with age and use