The first person in the world who was visited by the idea of creating a standard of time was an outstanding Russian scientist Dmitry Ivanovich Mendeleev. He also had the idea of creating a room in which an ultra-precise clockwork would function as efficiently as possible, counting the seconds, which are generally accepted units of time.

In 1902, a Russian scientist designed a building where a reference clock mechanism could be located — a special tower with a perfectly round dome crowning it. According to Dmitry Ivanovich's idea, in addition to the clock, this building had to house an astronomical observatory and a unique installation, with which it would be possible to determine acceleration of free fall.

The tower, which can be seen today, was soon erected. The watch installed on it was designed and manufactured by the specialists of the German company Neumeyer & Sons and fully complied with all standards. It was a unique watch at that time, it had an original dial — not twelve, but twenty-four hour divisions. Every twelve hours, the clock reproduced a signal that was transmitted by means of a special device to the laboratories located in the premises of the Main Chamber.

After a while, this signal was transmitted via a direct armoured cable to other city clocks — in the Winter Palace, the General Staff Building and the Ministry of Finance of Russia.

Nowadays, the clock, the installation and accuracy of which was controlled by Mendeleev a hundred years ago, no longer serves as a standard of time, but continues to work exactly as well. In the sixties of the last century, their mechanical drive was replaced by an electric one.

The tower with a unique clock is located on the territory of the All-Russian Research Institute of Metrology named after Dmitry Ivanovich Mendeleev. Special excursions are organized for everyone who wants to compare their watches with a century-old but high-precision mechanism.