Signing of the <a href="https://en.wikipedia.org/wiki/Metre_Convention" id="mwzg" rel="mw:WikiLink" title="Metre Convention">Metre Convention</a> by 17 nations leading to the establishment of the <a href="https://en.wikipedia.org/wiki/International_System_of_Units" id="mwzw" rel="mw:WikiLink" title="International System of Units">International System of Units</a>.