In that machine the form of type was made to traverse horizontally under
the pressure cylinder, with which the sheet of paper was held in close
embrace by means of a series of endless tapes. The ink was placed in a
cylindrical box, from which it was extruded by means of a powerful
screw, depressing a well-fitted piston; it then fell between two iron
rollers, and was by their rotation transferred to several other
subjacent rollers, which had not only a motion round their axes, but an
alternating traverse motion (endwise). This system of equalizing rollers
terminated in two which applied the ink to the types. (See _fig._ 915).
This plan of inking evidently involved a rather complex mechanism, was
hence difficult to manage, and sometimes required two hours to get into
good working trim. It has been superseded by a happy invention of Mr.
Cowper, to be presently described.
In order to obtain a great many impressions rapidly from the same form,
a paper-conducting cylinder (one embraced by the paper) was mounted upon
each side of the inking apparatus, the form being made to traverse under
both of them. This double-action machine threw off 1100 impressions per
hour when first finished; and by a subsequent improvement, no less than
1800.
[Illustration: 916