1657 This clock is important and controversial. Not everyone thinks it is genuine. If it is, it would be the earliest known timepiece controlled by a pendulum, made by Jan van Call to Christian Huygen's design in 1657. The new pendulum technology radically improved timekeeping and was fundamental to the progress of science, astronomy and navigation. The upper half of the dial boldly shows the minutes and seconds, which can noy be measured accurately using the new pendulum technology. Jan van Call, Nijmegen 30-hour duration, weight driven, endless rope maintaining power, verge escapement, pendulum control
aperture=f4.0 focal length: 60.0 mm exposure 1/160 sec ISO: 3200