Moving time

In the summer of 2019, a unique clock was moved to TU Delft Library. The clock, a precise pendulum clock dating from 1901, was made by German clock manufacturer Strasser & Rohde. In 1904, it was placed in the former Geodesy building at Kanaalweg 4 in Delft and was connected to the observatory there.

After the loan agreement ended in the summer of 2019, the clock was disassembled by clock technician Gertjan Westerbeke, and moved to the library’s academic heritage depot. Due to its great historical value, the clock is part of the Museum Collection.

Up until 1909, time was not regulated in the Netherlands. Each city or region had its own time. However, the arrival of the railway system meant that a standard time became necessary. The Dutch government implemented Amsterdam Time in May 1909. The benchmark for time was the Westertoren church tower clock in Amsterdam.

In Delft, the Strasser & Rohde clock was connected to the observatory of the Geodesy building, which made measurements to measure the Mean Solar Time. Until 1930, it was therefore one of the most accurate clocks in Delft to depict the exact time.

Not only is the clock of historical value, the clockwork mechanics also make it an impressive object. The timepiece, for instance, is equipped with sapphire bearings, which show no signs of wear even after 118 years. Furthermore, the steel pendulum is compensated to take account of changes in temperature. It includes a column filled with mercury at the bottom. If the pendulum expands with increasing temperature, the mercury level in the column also increases. Because these are precisely coordinated with each other, the pendulum’s centre of gravity, and therefore the pendulum time, always remains constant.

The clock is currently stored in the Library’s depot, until a new loan location is found.