A Novel Tesla Steam-Electric Clock

Among the various wonderful inventions of Dr. Nikola Tesla we find one of the most interesting clocks ever made, and the accompanying photographs show the necessary equipment for this highly ingenious and novel electric clock.

The clock proper, shown above, is apparently no different from any other standard clock. However, the mechanical movement has been removed and substituted by another special movement linked up with an alternating current motor of special construction which can be seen at the extreme right of the clock. The field consists of a number of rectangular coils placed in toroidal form and connected in series. The rotor or armature is constructed of a circular iron disc, the periphery of which consists of a large number of poles. The speed of this rotor is controlled by the current input. Connections between the rotor shaft and that of the clock hands is obtained by means of a number of reduction gears properly calculated so as to obtain the correct time, when the hands are acted upon by the motor. 

The source of current for driving this remarkable electric clock motor is obtained from an alternating current generator of very unique construction and design, this machine being illustrated here. It consists of two steam or comprest air cylinders, built in one frame as shown. A piston is placed in each of the cylinders which operate alternately with respect to each other. The connecting rods of each piston are linked with a vibrating membrane of each dynamo; these are seen at each end. A coil is placed on each membrane and connected to a special commutator. The electro-magnet or coil is operated in a powerful magnetic field, made up of two powerful electro-magnets placed at each end of the generator. These coils are excited by a direct current, while the coil on the vibrating disk is utilized to supply the alternating current.

The operation of this type of machine may be explained as follows: When the steam or comprest air is permitted to enter the cylinders, thus operating the pistons and in turn vibrating the armatures or coils, an electro-motive force is induced in the coil by virtue of being moved in the magnetic field surrounding it. The period or frequency of vibration of this current depends upon the rapidity of the armature movement. Both generators are linked in such a manner that an alternating current of uniform form and periodicity is obtained.

The motor on the clock is connected with this special generator and the current is so adjusted that a uniform velocity of the rotor is always obtained in order to obtain absolutely correct time from the clock.

A large number of such clocks were installed in the laboratory of Dr. Nikola Tesla a number of years ago which are driven by a single generating unit. It is said that the accuracy of time attained by this ingenious clock system is far better than with any other system known.