Ruler

A simple ruler with divisions by centimeters and millimeters has existed for more than two hundred years. However, during the excavation of Pompeii archaeologists found carefully cut plates, with the help of which the ancient architects carried out their drawings. In the Middle Ages, German monks used thin lead plaques to mark lines and columns on parchment sheets. In a number of countries in Europe, including in Ancient Rus, for these purposes iron bars were used. In the annals they were called "shilsami".

A simple ruler with divisions by centimeters and millimeters has existed for more than two hundred years

When the revolution began in France in 1789, the academicians were instructed to introduce a new system of measures. For unit length, a forty-millionth part of the geographic meridian passing through Paris was accepted. His arc was carefully measured by French scientists on the stretch from Duques to Barcelona. Then in Paris, two platinum rulers with a width of 25 mm and a length of 1 meter were made. This standard was called the "republican meter".

The wooden ruler with metric divisions was at first available only to academicians. Then such rulers were made for the Parisian students, first of all for students of the higher Polytechnical school. In ordinary school classes, the ruler passed at the very beginning of the 19th century. In Russia, the "republican" lines came in 1812 as military trophies. But they started production only after 1899, when the gradual introduction of the metric system of measures began on the initiative of D.I. Mendeleyev in Russia.

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