Congreve clock
...that a Congreve clock uses a rolling ball rather than a pendulum to regulate the time?
...that a <b id="mwDHc"><a href="./Congreve_clock" id="mwDHg" rel="mw:WikiLink" title="Congreve clock">Congreve clock</a></b> uses a rolling ball rather than a <a href="./Pendulum" id="mwDHk" rel="mw:WikiLink" title="Pendulum">pendulum</a> to regulate the time?