An early Dutch electrical longcase regulator, signed on the glass dial F. C. de Jong AMSTERDAM. This is the oldest electrical clock known from the Netherlands. It is most remarkable that the pendulum drives the movement, which in its turn is kept moving by one impulse per two oscillations. This works as follows: a small weight drops and the impulse this causes is transferred via a spring to the pendulum. The weight is then returned to its original position by an electromagnet. In devising this system De Jong was inspired by the Froment pendulum which is also kept in motion by a spring. The advantage of this system is that the intensity of the impulse is independent of the electrical current. This results in the pendulum having an extremely regular swing. As the impulse takes place at the moment when the pendulum is moving at its greatest velocity, the pendulum has optimal freedom of motion. The clock has a seconds pendulum with gridiron compensation and a 16kg bob, which causes the pendulum to remain in motion for a long time. • Height: 34 cm. • The maker, F. C de Jong(1826-1876), was a watchmaker in Amsterdam. An experimental version of his clock was exhibited at a metal fair in The Hague in 1863. The present clock was displayed at an exhibition in the Paleis voor Volksvlijt in Amsterdam. In 1868 De Jong was commissioned by the Amsterdam Council to design a public electrical clock system to show the time around the city of Amsterdam, which would have been the first of its kind in The Netherlands. His design was, however, rejected by the council. Apart from clock movements De Jong also developed his own type of battery.