Norton screwcutting gearbox--primary reduction gears. The drive to the box was through the normal means of changewheels with, in addition, a set of gears carried between the bed rails beneath the headstock - the more normal means of obtaining extra pitches would have been built into the gearbox itself. More details at the top of this page
Inside the power-feed apron
Worm and wheel drive to the power-feeds' drive shaft - by which means a much finer rate of both sliding surfacing feed could be obtained.
To the right the leadscrew clasp nuts--hinged bar assembly provides an
interlock to prevent the power being engaged at the same time as the leadscrew