"Self -preferred and self -propelled ..."

To the 605th anniversary of the first tower hours in Moscow

For a long time, medieval cities did without tower hours. Life flowed measuredly and leisurely, the time was practically not noticed, and there was only a scream of a rooster that proclaimed a new day, and the sunrise and sunset, sharing a day for day and night. Sunny watches were convenient only on clear days and in Rus' rarely met.

Mechanical tower watches appeared in Europe at the end of the XIII century. Although some historians believe that the first mechanical watches were created in Magdeburg monk Herbert, who later became the pope, the Roman Sylvester II, it was not known for certain whether Herbert’s watch was truly mechanical or still sunny. It is reliably known about the installation of the first mechanical watches on the Tower of Westminster Abbey in England in 1288. The next century, the tower hours appeared in many large cities of Europe.

In Moscow, the first city clock appeared in 1404, when the Grand Duke Vasily Dmitrievich built his new courtyard in the Kremlin, behind the Church of the Annunciation, and put on it the “part” - a tower with a clock. A clock for the Moscow prince was made by a monk Lazarus. It is known about this person that he was born in Serbia, was tonsured in monks in one of the male monasteries on Mount Athos in Greece, from where he came to Moscow.

The installation of the clock in Moscow was an amazing event, the mention of which was preserved at once in three annals. The most contemporaries were surprised by an independent fight: “It was not a man who hit [in the bell], but humanoid, selflessly and independently,” -
It was said in the annals. The mechanism of the clock could be seen outside, but the townspeople could not understand his work, because everything was “translated and attracted” there, and therefore caused a burning interest and curiosity that forced to come to the clock again and again.

Indeed, the Lazarus mechanism should have not been so simple: in those days, 12 night hours and 12 daytime were different from each other, which means that Lazarus had to provide either switching between two mechanisms with different strokes, or a change in the speed of one single watch mechanism. In Europe, one and other design options were used, but which one was chosen in Moscow is not known. The Moscow clock had one motionless arrow and a rotating dial, on which there were 12 Old Slavonic letters, counting the time. One of the annals claims that the clock also showed the phases of the moon.

The clock in the medieval city was a rare and expensive pleasure, which the townspeople were rightly proud of. The annals say that Vasily Dmitrievich spent more than 150 rubles on his part - in those days a very large amount even for the Grand Duke (for comparison: the annual tribute of the Golden Horde amounted to 1000 rubles, and collected it with the whole principality). The gears of the clock mechanism were made by blacksmiths. They were so large that they had to be collected and fastened in parts. The already assembled mechanism was driven by weight of the weight, which spun the shaft with a gear wheel. The diameters of the wheels in the transmitted mechanism were calculated so that the period of rotation of the dial was 12 hours.

The clock required permanent maintenance: raising heavy cargo, lubrication and correction of inaccuracy, which was noticeable after a few days. The course of the clock was regulated by the Bilyan - a sawn -shaped crossbar with cargo at the ends, hesitating if it is removed from a state of equilibrium. The Bilyan was planted on a spindle with two palettes (plates). When the spindle, under the influence of Bilyan’s vibrations, turned into one direction or the other, the fits in turn came between the cloves
The large trigger, making its rotation uniform under the influence of weight weights. But Bilya himself does not have its own fluctuations and therefore moves unevenly, which gave a serious inaccuracy of the course. This problem was solved only in the 16th century, when the pendulum invented by Galileo appeared in the watch.

However, the first hours were automatic, that is, independent, mechanism, which surprised contemporaries. Their development and improvement changed the entire technique of that time, and the watch itself changed the life of the townspeople. The clock was very large and clearly visible from all over the city, and therefore served as the main guideline not only in time, but also in space. Meetings were scheduled for them, began and finished work. Life gradually began to accelerate, and time to play an increasing role. After installing mechanical hours in Moscow, instructions of not only days appear in the annals, but also an hour for many events.

Nikita Khanbekov , physicist, diplomomal MEPhI