In the spotlight – the Puja alcohol clock

Download PDF

Are these electric clocks?

Sure they are, so here’s the story! Puja is believed to come from the German word Pulshammer” which means pulse hammer……. The patent was granted to Karl Jauch from the Jauch und Schmid Uhrenfabrik (Jundes) in Schwenningen, Germany in 1941. The production of the clocks started in 1945.

How does it work? At the bottom left sits a black resistor that acts as a heater; it runs from the 220 mains voltage. It warms up the alcohol in the lower glass container to its boiling point at 78 degrees Centigrade. The alcohol expands and slowly flows into the top right container. Gravity then makes the unit turn a quarter and the next container is heated. This goes on and on and makes the containers rotate continuously around its axle. The rotation acts as the the winding key for the clock. To see the clocks in full operation click here.

In most clocks only alcohol is used in the containers,however there are a few clocks known with much smaller containers filled with alcohol and mercury. In that case the alcohol is pushing up the mercury and thanks to the bigger weight of the mercury even these small containers do their winding job perfectly.

Complete clocks with their original case are rarely found, probably because most cases are equally huge as ugly…. The cases were cheaply made and sometimes beautifully decorated……….at least to the taste of the 1940s…
So, sure they are electric clocks, visit the album of the maker here

Gijs Veraart



One Comment

  1. There could be another reason for the name PUJA.

    In the catalog of the exhibition “Alle Zeit der Welt” of the “Deutsche Gesellschaft für Chronometrie” (DGC), there is the following note associated with the PUJA clock:
    “Der Vater des Verleihers wurde 1940 von Karl Jauch dem Vater DES ERFINDERS PAUL ULRICH JAUCH beauftragt, den Schutzanspruch für diese neuartige Uhr zu beantragen.”
    (The father of the Owner was commissioned in 1940 by Karl Jauch, the father of the INVENTOR PAUL-ULRICH JAUCH, to apply for a patent for this new clock.)

    So PUJA would come from Paul-Ulrich JAuch. But the patent (DE 714.893A) named Karl Jauch as Applicant and Inventor. So this might be a rumour only

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.