Most likely in the 1930ies, the manufactury from Herrmann Friedrich Bauer in Pforzheim, Germany, launched their 10 1⁄2 ligne movement Bauer 10 1⁄2 old. The suffix “old” was added later, when the relaunched version of this movement was available as Bauer 10 1⁄2 new
You can see the state of the art of that time: Brass/gilt colored base plate with ruby bearings for all fast turning gears.
Even when it’s not visible at the first glance, this is a pillar construction. It is hidden very well by the cocks and bridges, whose edges are solid and go down till the base plate.
We have the classical gear train with directly driven center minute wheel, third wheel, seconds wheel at 6 o’clock (with prolonged axle, which carries the decentral seconds hand on the dial side) and escape wheel.
Of course, the screw balance is not yet shock protected. It beats with 18000 A/h and regulates a classical swiss type pallet lever movement.
Its exact beat frequency can be adjusted with a long regulator arm and and engraved scale on the balance cock.
There are no surprised on the dial side, it’s all state of the art of that time. As usual on better movement, there’s a yoke winding system.
If you look exactly, you can spot the mountings for the riveted pillars.
|Caliber:||10 1/2 alt|
|Number of jewels:||15|
Nickel screw balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||pillar construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||4 hole(s)|
|Functions:||hour, minute, decentral second|
|Size:||10 1/2''' (measured: 23,0mm)|
Flume: Jacob 1942|