308 FEDERAL REPORTER. �and thus a very rapid series of vibrations and interruptions of the circuit may be effected. It is evident, therefore, if the circuit of this breaker is inoluded in or forms part of the main circuit which passes through the priraary coil, that at each break an iûduced current will be set up in the seeondary coil, as with the other circuit-bi'eakers. In figure 10 is shown an electro-magnet and armature in which the retractile force of the armature is made adjustable. This is oftentimes im- portant. The coils i are secured to a base board and enclose a bundie of soft iron wires, seen projecting slightly at a. Between the two pillars x is suspended the vibrating electro- tome or circuit-breaker. ^r is a small cylinder of soft iron attached to one end of the lever e, which passes through or is otherwise secured to the vibrating shaft k. The other end of the lever dips into a mercury cup m, fixed upon the metallic strap V. On the strap b is another mercury cup of brass, into which descends a branch wire h, from the vibrating wire e. Arising from the shaft k ia a, atiS brass wire, in the form of a bent lever, carrying upon its horizontal poi'tion o a bail/, which is movable on a screw thread from end to end of por- tion 0. It will be seen that, as the bail is moved towards the extremety o, it increases the weight of the long arm of wire e. If the coils and magnet be charged by the current from the battery, and the current passes from the strap b to b', through the lever e and mercury cups, the magnet a will attract the hammcr piece g, and, in so doing, will lift the end oflever e out of the mercury in cup m and break the cir- cuit, when the armatare-lever, being drawn back by the retractile force of the weight, will again close the circuit. As the weight /is further removed from the centerof vibration, the more magnetic power will be required to move the ham- mer g; its distance from magnet a remaining the same the greater is its retractile force, and the more suddenly and completely will the circuit be broken in cup m. The dis- tance between g and a can be varied by slightly bending the wire e." �The text of the specification of the original patent is, in the foregoing parts, substantially identical with that of the ��� �
