hanging mechanisms _F_ on each side of the machine.
These feed boxes contain gears of different sizes, and by changing the
combinations of these gears, the amount of feed is varied. Five feed
changes are obtained on this machine by shifting lever _E_, and this
number is doubled by shifting lever _G_. By having two feed boxes, the
feeding movement of each head can be varied independently. The direction
of either the horizontal or vertical feed can be reversed by lever _R_,
which is also used for engaging or disengaging the feeds. This machine
is equipped with the dials _I_ and _I_{1}_ which can be set to
automatically disengage the feed at any predetermined point. There are
also micrometer dials graduated to thousandths of an inch and used for
adjusting the tools without the use of measuring instruments.

The work table _B_ is driven indirectly from a belt pulley at the rear,
which transmits the power through gearing. The speed of the table can be
varied for turning large or small parts, by levers _J_ and _K_ and the
table can be started, stopped or rotated part of a revolution by lever
_L_ which connects with a friction clutch. There are corresponding feed
and speed levers on the opposite side, so that the machine can be
controlled from either position.

The heads can be adjusted along the cross-rail for setting the tools by
hand-cranks _N_, and the tool slides can be moved vertically by turning
shafts _V_ with the same cranks. With this machine, however, these
adjustments do not have to be made by hand, ordinarily, as there are
rapid power movements controlled by levers _M_. These levers
automatically disengage the feeds and enable the tool-heads to be
rapidly shifted to the required position, the direction of the movement
depending upon the position of the feed reverse lever _R_ and lever _D_.
This rapid traverse, which is a feature applied to modern boring mills
of medium and large size, saves time and the labor connected with hand
adjustments. The cross-rail _C_ has a vertical adjustment on the faces
of the right and left housings which support it, in order to locate the
tool-heads at the right height for the work. This adjustment is effected
by power and is controlled by levers at the sides of the housings.
Normally, the cross-rail is bolted to the housings, and these bolts must
be loosened before making the adjustment, and must always be tightened
afterwards.

The function of these different levers has been expl