Maker, Hahl Automatic Clock Co, Chicago, Illinois, USA. serial no. 318, made in 1913.

The photos below show the movement before restoration. Considering the state that these movements are normally found in, especially the rubber bellows, this was in remarkable condition. The rubber was in a perfect operable state after nearly 100 years!

The movement is a veritable Rube Goldberg device to see in action. Once per minute the large vertical fly is released and all of the wheel works begin to turn, simultaneously the pivoted balance tilts to one side, the minute hand advances and the spring remontoire is wound 1/8 turn. Various levers are raised and released opening and closing the air needle valves which are attached to the bellows which alternatively supply compression and evacuation to the air lines.

The first photo below shows the one-minute spring remontoire and frictionless crutch system. The grooved, pivoted plate when in place, is in a horizontal position. The pendulum has a pivoted, sharp-edges wheel that rides in this groove. The second photo shows the needle valves that supply the air that is alternately compressed and evacuated thus pushing and then pulling a plunger in the slave to advance a ratchet wheel much like an electric solenoid does in a conventional slave.

The two weight stacks together weigh 156lb and drive the two great wheels simultaneously through a common pinion. A testament to the huge amount of energy that this system requires for operation. Even large tower clocks do not require such weight for the time train. The next photo shows one of a pair on manometers that verify the air lines are air tight.