Kadigaram Uruvaana kathai / கடிகாரம் உருவான வரல&

Circa 1583 Galileo invented the isochronism of the pendulum during the year, but it was Huygens who used it on the clock. And completed the precision pendulum clock. Hoggens patented it in 1667, and in 1673 he issued a ""pendulum clock"".