at Bouillon and Sedan, Château-Renaud, and Rethel also struck quarter écus, with their own arms replacing the royal arms. By the 17th century this écu d’or would rise in value from 3₶. to more than 5₶., while the hammered silver quarter écu struck until 1646 would rise in value from 15s. to 1₶. Silver Louis or écu of 1641 This still did not give France a coin which could compete with the thalers which were popular in Germany. Moreover, French coins were still made by hand, so precious metal could be illegally shaved from the edges of the coins before passing them on. Finally, the écu d’or was made of 23 carat gold, which was not the international standard. Louis XIII fixed all this. He installed coinage making machinery in the Paris mint and replaced the écu d’or with the Louis d'or in 1640. In 1641 he introduced a thaler-sized silver coin originally called a Louis d’argent, issued at 9 to a French Mark of silver, 11/12 fine (24.93 g fine silver), and valued at three livres tournois - the same value in which the écu d’or was stabilized in 1577. This new 3₶. coin also came to be called an écu. Silver écu of 1726 From 1690 to 1725 rates were unstable, resulting in the discontinuation of the Louis d'argent in favor of the new silver écu. In 1726 it was first issued at issued 8.3 to a French Mark of silver, 11/12 fine (or 27.03 g fine silver), and valued at 6₶. The silver écu was further broken down into a value coin (huitième d'écu), a value coin (the quart d'écu) and a value coin (the demi-écu). All had the king's bust on the obverse and the royal coat of arms on the reverse. This silver écu was known as the laubthaler in Germany. It circulated in Southern Germany at 2.8 South German gulden. In Switzerland it was worth four Berne livres or four francs of the Helvetic Republic. For more on the 17th-18th centuries currency system, see Louis d'or, livre tournois and Italian scudo. French Revolution The silver écu disappeared during the French Revolution and was replaced by the franc at the rate of 6₶. = 6/1.0125 or 5.93 francs. At 4.5 g fine silver per franc this implied each écu contained only 26.66 g fine silver. But the 5-franc silver coins minted throughout the 19th century