Probably built in the late 1940s or early 1950s, when machine tools of all types were in short supply, the Hercus Cylindrical grinder was a solid machine that used Whitworth nuts and bolts. It had a centre height of 4.5 inches and took 13 inches a distance between centres of 13 inches.
The headstock spindle - fitted with a 1.75" Whitworth thread for the mounting of chucks, etc., was formed with a No.3 Morse taper and the tailstock a No.2
Work could be driven between dead centres or a live centre on the headstock. The dead centre drive in the photographs was made by the present owner in brass and is not original.
Able to be swivelled, the headstock allowed large angles can be ground while the table swivel (graduated in inches per foot), permitted the grinding of tapers. The wheel head was fixed and did not swivel.
In front of the wheel grinding head was a mounting slot for an internal grinding attachment driven by a flat belt from the wheel-drive spindle. Unfortunately, this accessory has not survived with the  machine.
The automatic reversing feed drive was an all-mechanical arrangement that incorporated an adjustable ratchet 'auto-in' feed, which was disengaged when approximately 2 thou from the end of the job to allow manual control to the finished size. A video of the mechanism is here
Ten inches in diameter, the grinding wheel was mounted on a carrier that, unusually, had no provision for balancing - however, there was a useful hole in the tailstock to hold a diamond dressing stick .
Four separate electric motors were fitted, these driving the wheel head, headstock, feed drive and coolant pump.
Sliding on plain, inverted V-ways, the table was originally lubricated by felt wipers underneath. However, the present owner, after scraping the worn slides flat, converted to a roller lubricating system running in a reservoir copied from his Browne and Sharpe grinder.
He reports that the Hercis is "A good, accurate machine but more designed for production work than super finishing".
Thanks to Murray Ballinger for the pictures and information..