This is really quite an intricate device.  The bronze 'fixture' or armature, that attaches to the rifle, has pivots on its ends that link it to the machine.  The cylinder, which holds and marks the miniature targets, apparently lies on the machine 'bed' and is actuated by a cable.  (I've since learned, on some machines, the release of the trigger completes an electric circuit.  There is a dry battery located in the machine's pedestal.  An electro-magnet propels the sub-target into a pointed rod to be pierced, thus recording the 'shot'.  This is reported in the 1906 Wilkinson brochure).

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