Technical description of this Bisamapfeluhr:
The housing is made from copper, the outside is mercurial gold plated and the inside is mercurial silver plated. The clockwork consists completely out of iron apart from a replaced brass crown gear.
Housing diameter: 4,5 cm
Housing weight: 38,5 g
Clockworks diameter: 3,60 cm x 3,55 cm
Clockworks weight: 54,1 g
Total weight: 92,6 g
From the clockwork, the watch shows no technical equipment as well as solutions or elements, which are unknown or not proven for the first portable watches.
As time indicator there is only an hour hand available, the simply engraved clock face shows the same division.
After opening the bottom half of the sphere, the iron works is visible. After loosening two latches joint to each other with a spring, the work, which is perfectly fitted to the housing, can be loosened and removed.
The iron baseplate becomes visible with the hour wheel and its 4 teeth gear. The top plate is skeletonised.
The large, circular balance-wheel with the pig bristle regulation is visible (proven around 1430 in the Burgundy watch). Clearly recognisable is the finely clean iron workmanship on the works pillar and the plates, like e.g. the smooth surfaces, parallel edges and angularity of the surfaces. The confident guiding of tools is recognisable here.
During an earlier repair, the iron worm gear was turned off and a brass crown gear was pressed on. This damage could have been caused by the breaking of a spring. Furthermore, 2 defective 5-gears were replaced with new 6-gears. (One 5-gear still exists).
The worm gear limiter for restricting the winding is worked precisely. The spring housing base has a notch, the wall has a „nose“ as a counterpart so these parts can only be fitted together in this position; during the disassembly and the assembly, the spring housing will therefore never „tumble“.
The regulating arm with the pig bristles is tightly riveted to the plate edge; the swivelling to achieve a regulation is therefore ensured for a very variable adjustment. The arm is furnished with 3 holes for 2 bristles. The inner hole is necessary if the arm needs to be set very far to the outside so the balance wheel can sway evenly.
The arrangement of the double pressure spring for the closing latch is very beautifully solved.
All parts show a neat working, a thought through placing and a good room division. The blocks have been scratched and bruised by the frequent testing and fitting.
The coarse rotary grooves on the spring housing and the plates can be seen, which lead to the conclusion that the iron parts were made with a very slowly turning „lathe“.
Especially notable is a soldering at the carrying loop, exactly at the place where the opened lid with the loop touches the standing surface. This wear can only be the result from long usage. Furthermore, one of the 3 feet at the bottom of the housing shows more extensive wear. This can be explained that this foot is located under the heavy spring housing.
Also notable is the same material strength of the balance-wheel hoop and the upper plate of each approx. 1.4 mm and also the exactly slanted angle. This allows the conclusion that the balance-wheel and the plate are made from one forged piece of iron and that the balance-wheel hoop has not yet been replaced.
The housing is an embossed copper housing in a spherical form, hinged. Upper and lower bowl are arranged on a joint hinge. On the base there are 3 feet. The top side has 12 gaps in air bladder form.
And here you can see the watch @ work..
Just click on the image to see the movie
Source : http://www.peterhenlein.de/