The shaft of P can be readily put in gear with a powerful engine for the purpose of hauling back the cable should it be found necessary to do so.
A horizontal arm fixed to a vertical shaft in gear with the mechanism sweeps over these pins at the rate of about two revolutions per second.
In many of the old kinds of two-revolution machines, owing to the cylinder being geared separately from the type bed, it was apt to be occasionally thrown out, but in the Miehle, for instance, it is only out of gear in reversing, and in gear while printing.
While the engine in gear is coiling in its rope and drawing the plough towards itself, the rope of the other engine is paid out with merely so much drag on it as to keep it from kinking or getting ravelled on the drum.
The inking arrangements are usually very good, for, by a system of racks and cogs which may be regulated to a nicety, the necessary distribution of ink and rolling of the printing surface runs in gear with the travelling type bed or coffin.