Unlike so many similar lathes made during the late 1800s and early 1900s - that lacked any maker's identification - this backgeared and screwcutting lathe carries a bronze badge proclaiming "CLARK BURTSAL & C°. LONDON and SHEFFIELD".
Although now missing many essential parts, it's clear that this is a lathe designed in the late 1800s -  clues to its age being the spindle end thrust taken by a plate mounted on posts outboard of the left-hand spindle bearings, the backgears and the bed-mounted rack both being of coarse pitch and the deep curve of the bed around the detachable gap section.
Now resident in Australia, if the Clark Burtsal was made in the steel city of Sheffield is not known, but it is very likely with other lathes manufactured in the city including those by Adept, Bunting, Faircut, Flexispeed, Portass, Record and Roper & Wreaks.