The great wheel (bottom wheel) has the cable drum in front of it.  Two pieces of 30 lb fishing string serves as the weight cables.  Between the cable drum and the wheel are the clickers that engage the ratchet (not visible).  The clickers are gravity operated.  To the left and above is the the center wheel.  The pinion cap of the center wheel has a fender washer glued on the outer end..  To the right of the cap is the canon pinion that rides on the same axle as the center wheel.  On the back of the canon pinion is a piece of magnetic tape that attaches itself to the fender washer.  This provides the power to turn the dial train.  One can set the correct time by turning the minute hand.  The magnetic tape will slip on the fender washer allowing this action.