Clock No. 1

Photo of the front side of clock No. 1 The first clock made by Rasmus Sørnes is a mantelpiece clock. Based on the years engraved on the front dial, he appears to have been working on this clock between 1937 and 1947, although reference [1] claims it was completed in about a year.


  • Standard time
  • Greenwich Mean Time
  • Sidereal time
  • Moon phase
  • High and low tide
  • Sunrise and sunset time
  • Julian number
  • Earth globe showing day and night
  • 2-D firmament
  • Orrery with six planets
  • 28 year solar cycle
  • 19 year lunar (Metonic) cycle
  • Julian Calendar
  • Solar and lunar eclipse indication

The firmament is visualized on a two-dimensional dial, holes are drilled for the larger stars and the dial is illuminated from behind to make the stars visible in the evening. A switch allows the clock to be run forward and backwards in time.

Photo of the right side of clock No. 1


The clock is controlled by Sørnes' own invention, an electromagnetical balance wheel escapement. It feeds the system with a constant revolution of one rotation per second and is in this clock powered by two 1.5 V batteries. He experimented with the escapement for many years but eventually resorted to more traditional solutions.

Clock No. 2 and 3 uses the same escapement, but clock No. 3 has an additional synchronous motor and a pendulum driven escapement installed, and in clock No. 4 only the synchronous motor and pendulum driven escapement remains.


It has been told [1] that when finished, he was not satisfied with the result. The accuracy of the celestial orbits suffered as the calculations were based on regular calendars without full correction of the irregularities. Nevertheless, he must have learned alot from this construction, and he kept improving the design in the coming clocks.


The clock is in private possession by the Sørnes family, and is temporarily on display at Inspiria Science Center, Sarpsborg.

Photo of the rear side of clock No. 1

Source reference

  1. Tor Sørnes: The clockmaker Rasmus Sørnes, Sarpsborg 2008
  2. Erik Ødegaard: Sørnes astronomiske ur nr. 1
  3. All images in this article are copyright Erik Ødegaard.