Ship chronometers  


Manufacturer:                     A. Arway, Beč

Year of production:                      unknown

Serial number:                                No. 28

Oscillator:                              Period 0.5 s

It's unknown when the clock was set to operation, but this chronometer has been at Geophysical Institute from the first time-correction measurements done by A. Mohorovičić with the passage instrument in 1892. It was often used to “transport” the accurate time to remote locations.



Manufacturer:                      Ulysse Nardin

Year of production:                              1913

Serial number:                               No. 549

Oscillator:                                Period 0.5 s

The clock was set to operation on December 31, 1913. It was the backup clock used for time-signals on
Wiechert seismographs


The clocks at Grič were operating until October 17, 1984. The watchmaker Ivan Geresdorfer thoroughly cleaned, fixed and reinstalled the clocks, so that they were operating again from December 11, 1984 until 1996. Up to the end of the homeland war (1991-1995) these clocks, with all the necessary equipment, were able to transmit time-signals within hours, if needed.