Almost certainly dating from the period circa 1870 to 1895, the very rare (just seven are known to have survived) the A. Halls backgeared and screwcutting lathe was manufactured in a most unlikely location, the seaside town of Yarmouth, England. Well-made and with a design typical of its period - and the sort of machine turned out by many of the more ambitious small engineering concerns at the time - the early models had a lightly constructed headstock with the end thrust of the (solid) spindle taken against a cross-bar mounted on posts outboard of the left-hand bearing. The spindle may well have been hardened and ran in a cone socket, directly in the cast-iron of the headstock - the free graphite in which ensured a long, trouble-free life. A 3-step pulley was provided, for drive by a round leather "gut" rope originally from a foot-treadle and flywheel assembly - a system that would have provided sufficient motive force for most small jobs and, in backgear, the capacity for some heavier work.
With a flat top and V-edges the bed was of the traditional "English" type with a rather short permanent gap provided at the headstock end. Cast as one with the apron, the saddle incorporated a useful T-slotted boring table (either plain or with either two or three transverse T-slots) to which was bolted a compound slide rest free to be positioned as the operator wished. Driven by crank handles, the slide's coarse-pitch feed screws were of the correct left-hand pitch and so avoided that problem common to so many contemporary small lathes of "cack-handed" operation - where turning the screw to the right retracted rather than advanced the slide. As was common at the time, the gear on the crank-handled carriage feed was connected directly to the leadscrew, making a slight, fractional rotation of the handle produce a disproportionately long and difficult-to-control travel along the bed.
Drive to the 4 t.p.i. leadscrew was though through a tumble-reverse mechanism and coarse-pitch changewheels, of which the usual very large set, common in Victorian times, was provided.
Later lathes (an example is shown at the bottom of the page) followed prevailing fashion with the headstock made a little more rigid, spindle bearings increased in size and end thrust was taken out against the inside face of that on the left. The whole carriage was also redesigned with the apron being very much more substantial and the carriage drive crank handle replaced by a handwheel - although the gear on this was still connected direct to the leadscrew, though there is the possibly that the drive would have incorporated some form of reduction gearing.
If you have a Halls lathe the writer would be very surprised - and delighted if you would make contact. More pictures here and here