Beautifully engraved certificate from the Wenzel Pneumatic Clock Company of the District of Columbia issued in 1882. This historic document has an ornate border around it with a vignette of the U.S. Capitol. This item is hand signed by the Company's President and Secretary and is over 122 years old.
Pneumatic Clocks were had a master clock system. The pendulum-driven master clock system needed no electrical current to control the remote (slave) clocks which indexed every minute on a 'puff' of air. The master clock ran like a typical grandfather clock using weighted pulleys and a pendulum. The clock also has a small bellows inside. When the bellows push down, air is pumped through a closed system of tubes connected to the secondary or "slave" clocks, moving the hands on those clocks. These types of clocks were very accurate when operating properly. Pneumatic clocks were used in offices or government buildings where multiple clocks were located.