<a href="https://en.wikipedia.org/wiki/Emperor_Tenji" id="mwEA" rel="mw:WikiLink" title="Emperor Tenji">Emperor Tenji</a> of Japan introduces a water clock (<a href="https://en.wikipedia.org/wiki/Water_clock" id="mwEQ" rel="mw:WikiLink" title="Water clock">clepsydra</a>) called <i id="mwEg">Rokoku</i>. The instrument, which measures time and indicates hours, is placed in the capital of <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Ōtsu,_Shiga" id="mwEw" rel="mw:WikiLink" title="Ōtsu, Shiga">Ōtsu</a>.