What were the official platinum artifacts deposited in the French Archives in 1799 known as?

Mètre des archives and kilogramme des archives

By 1799, the intense labor of the geodetic surveys and subsequent calculations had produced the first physical representations of the newly defined fundamental units. These official standards, crafted from platinum for durability and accuracy, were deposited securely in the French Archives. These artifacts were formally titled the *mètre des archives* and the *kilogramme des archives*. Although the system was theoretically based on eternal natural standards (the Earth and water density), these physical objects became the practical, tangible reference points used for implementing and enforcing the metric system throughout its nascent years, serving as the benchmark against which all other measurements were compared.