The accuracy problem was so great that early clocks didn’t even have a minute hand. There was just an indicator on the dial, which was marked with 4 zones, indicating in which 15 minute zone one is. Some clocks of that era do feature a second’s hand, which is believed just to show that the clock is working. One of the breakthroughs of that century was the use of a pendulum, which was a weight to keep the coil wound up to keep a constant movement. The length of pendulum was made 99.38cm for a 1 second movement, and that’s when the majestic grandfather clocks became popular.