Arnold and Son is an unusual watch company, in that the name they brought back from the history of watchmaking is British and not Swiss. For a while they were part of the same company, British Masters, as Graham, another rejuvenated historical British brand, but they were bought by the movement maker La Joux-Perret a few years back. The upshot of that acquisition is some more interesting movement work from the brand, including this Equation Sidereal piece.
The watch shows the mean solar time (our time) on the right and sidereal time on the left. The 24-hour indicator at the top indicates for both, with the shape of hand determining which time scale is being represented. The two zones of time are driven by two distinct movements, hence the two balance wheels on the dial, only connected by case and the winding train. That allows them to do away with the complex gearing to create the differential between the two time-schemes. The second hand is connected to the mean-solar time.
Though a competent movement maker, La Joux-Perret is not known for their refined movements or their finishing, which is sadly visible when looking at the movement, either from the front or the back
 |  |
The movement is named caliber 1311, and has 42 jewels and with a beat of 21,600 has a power reserve of 42 hours. The case, in 18kt rose gold, measures 44mm and is water resistant to 30 meters.
(source)
A
Leave a comment