A very rare navigator deck monitoring timepiece, the so-called "combined sidereal and mean time watch".
Designed for the celestial navigation at sea, by Svante Elis Strömgren, Jens Olsen and Cornelius Knudsen (talented Danish watch makers who were the first to obtain the Danish patent 22822 of February 11, 1918 for their invention).
Case: silver, polished – Approx. Ø 60 mm – approx. 185 g
Dial: original enamelled dial – sub-dial with radial Arabic numerals 24 hours at "3" – sub-dial with radial Roman numerals at "9" and outer radial Arabic subsidiary dial with extra seconds, continuous 24 hours sidereal time and a chosen time zone or Greenwich time.
Two hands, single blued Breguet hand and a gold hand with sun indicator.
Movement: Anchor chronometer – Balance with gold screws – Nice setting mechanism – Wolf cogwheels.
Sidereal time is the time Earth needs to complete one rotation around its axis.
Because it is based on the rotation of Earth relative to the fixed stars, it is called sidereal time (sider = star in Latin).
A sidereal day is 23 hours, 56 minutes and 41 seconds.
The sidereal time mechanism can be connected to / disconnected from the time setting.
Very rare pocket watch, only 4 pieces known.
One of these 4 watches was part of the famous Gerd Ahrens collection and was auctioned in October 2007 for more than €30,000.
In very good condition – minor hairline cracks at the 24 hours sub-dial and scratches on the glass.
No box / No documentation.
Comes with a copy of the original manual created by Cornelius Knudsen Köbenhavn.
The photos are an integral part of the description.
Any defects that are visible on the photos are considered to have been described.
Delivered without warranty, in the condition it is in, assumed to be known by the buyer.
No compensations will be granted and returns will not be accepted.
- Manual winding
- Case material