Case for Electric Clock St Ann’s Square Manchester
Messrs Arnold and Lewis have just placed over the front of their shop in St Ann’s Square, a clock, surmounted by a ball, which is in direct communication with Greenwich. The ball, which is 18 inches in diameter, slides upon a mast 4 feet 6 inches high; and it is so arranged as to drop every day precisely at one o’ clock. The clock faces bear the words “Greenwich Time.” The case has been designed by Mr E Salomons, architect, and is being artistically decorated under his supervision. The clock is without the works which would make it self-acting, and the hands are moved by wheels controlled by a pendulum, whose motion is excited by an electric current coming from a battery within the shop. This battery is of four cells, and is connected with the works of a clock called the regulator, which is an exceptionally good time-keeper. Before Greenwich time was adopted by the railways, many gentlemen in Manchester and the surrounding districts, on market days availed themselves of this clock, then known as Mr Simmon’s, by which to set the mill clocks. A small galvanometer is fixed below the face of the regulator, which is connected by wire with the Observatory at Greenwich. About one minute before ten o’clock every morning the deflection of the needle of the galvanometer is signalled from Greenwich to prepare; and the return of the needle precisely at ten o’clock indicates the hour to a second. The attendant who is on the watch notes the difference, if any, between Greenwich time and the moment indicated by the regulator, and sets the latter right, if wrong. This clock is supplied with a mercurial pendulum, and, so far as the preliminary experiments have gone, it rarely requires to be altered. From the regulator an alternating current of positive and negative electricity passes along an insulated copper wire leading from the battery to the pendulum of the outside clock. This pendulum consists of a continuous coil of copper wire, so constructed as to oscillate over a pair of permanent magnets. The alternate attraction and repulsion of the two currents of the electricity coming from the regulator causes the movements of the outside clock to be perfectly synchronous with that inside.
A separate wire, charged from a battery of three cells, connects the regulator with the ball outside. The mast upon which it works is fixed perpendicularly to the clock case at the bottom, and at the top of the building. The ball is raised by a mechanical arrangement, the handle of which is just within the shop door. It rests when raised upon a half cut spindle, which is brought into position by means of a small lever held by the armature of an electric magnet. When the second hand of the regulator drops on the 60th second (at one o’ clock) a current of electricit passes instantaneously to the electro magnet outside, which withdraws the armature and the ball falls. A violent fall might derange some of the mechanism, and, therefore, there is attached to the ball a piston, which fits closely into a cylinder fastened to the clock case. This cylinder is closed at the bottom, and thus the ball is arrested in its fall by an air cushion, which enables it to settle down without any concussion. The clocks in the Royal Exchange are worked by electricity from a regulator in the master’s room, as we have already announced. But this enterprise by Messrs Arnold and Lewis’s is the first time that communication of the exact hour of the day has been made direct from Greenwich to the eye of the man in Manchester. It is intended that the ball should fall at one o’ clock on Tuesday the 16th inst, and daily thereafter.[Manchester Guardian 13 July 1872 Page 9]
Reference Manchester Guardian 13 July 1872 Page 9