Do you know? Why do we need notches on the edge of the coin?

Surely you have noticed that the edge (edge) of the coins is always covered with notches, or it made some inscriptions. These notches are made for a reason. Previously, large denomination coins were made of precious metals, gold or silver. Some cunning comrades guessed that you can cut or grind the edge of the coin. And if you do it carefully, it will be imperceptibly on the coin, and the cunning comrade received several milligrams of gold, from which it was possible to make fake coins or sell it as scrap to the jeweler. However, after such manipulations, the coin, the nominal value of which usually corresponded to the weight of the precious metal in it, became easier, and therefore was not valid in theory.  In order to avoid such fraudulent actions with coins, the ribs began to make incisions. After all, if such a coin will cut off the edge, it will be immediately visible and such a coin you will not accept, and make cuts at home is extremely difficult. In our time, coins made of precious metals almost ceased to produce, except for collectible and investment, but the notches on the edges of the coins survived and turned into an element of decor.  It is believed that the idea of making notches on a bunch of coins, as well as the invention of the gurtovalny mill belongs to the greatest English scientist physicist Isaac Newton, the very one who, according to legend, fell on the head of an Apple. The fact that Newton in addition to his scientific activities, in 1696-1727 he was in charge of the tower mint. But in fact, the idea of surtout coins originated even earlier. This idea was invented and implemented by a Frenchman, a specialist in coinage Pierre Blondeau, who worked at The Paris mint in the 40s of the XVII century. In 1649, at the invitation of Oliver Cromwell, he moved to England, where he engaged in the mechanization of coinage. And in 1662 invented hortovanyi mill and began to surtout coins-rings and inscription "Decus et tutament" ("Decoration and protection"). However, local masters of monetary Affairs, who feared the loss of work due to the mechanization of the process of coinage and defended manual coinage, launched a whole anti-propaganda dripping against Blondeau. In 1658 died Oliver Cromwell, Lord protector of England and patron of Pierre Blondeau, the country began the restoration of the monarchy in 1660, Charles II ascended the throne. Left without high patronage Blondeau under pressure from local chasers was forced to leave England. His machines were dismantled and taken to Edinburgh and the tower mint returned to hand-minting.  And only Isaac Newton, who headed this mint in 1696, returned to the ideas of Blondeau and made the "great minting" of the coins of England mechanically with the gurtovaniem of the ribs.