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The Encyclopedia of Horology

Copenhagen, Denmark · 1872 – 1945

Jens Olsen

Partially verified

Astronomical clock construction

Life & work

Jens Olsen designed and largely built an astronomical clock of great complexity, completed after his death, which displays a range of astronomical cycles including very long-period motions.

The project shows how a single designer's astronomical clock work continued into the twentieth century alongside industrial watchmaking.

Training, contributions & innovations

  • Designed a major twentieth-century astronomical clock
  • Documented the calculations behind its astronomical trains

Inventions & patents

  • No patent claim is asserted; the clock's wheel counts and calculations are documented.

Signatures & markings on surviving work

  • Not a commercial signing maker; the work is identified by the clock itself.

Collecting significance

Signatures on historic work were applied by retailers and by later hands as well as by makers, so attribution should rest on the movement's construction and on documented provenance rather than on the name alone. A specialist opinion is worth obtaining before any purchase made on the strength of a signature.

Related photographs

The Prague Astronomical Clock in Old Town - 8559
The Prague Astronomical Clock in Old Town - 8559 — Jorge Royan, CC BY-SA 3.0. Wikimedia Commons file page
Czech-2013-Prague-Astronomical clock face
Czech-2013-Prague-Astronomical clock face — Godot13, CC BY-SA 4.0. Wikimedia Commons file page

No confidently matched photograph of this subject has been found yet. These photographs show a closely related record, and are not examples of the type described on this page.

Sources & references

  1. Britten, F. J., Old Clocks and Watches and Their Makers
  2. Loomes, B., reference works on British and European clockmakers (edition-dependent)
  3. Museum catalogue entries for signed examples

Where sources disagree, the disagreement is stated rather than resolved silently.