First offered during the 1940s, this neatly-designed, stand-alone unit was intended to be held in place by a magnetic chuck - and hence capable of being mounted on almost any make or size of surface grinder. 
Measuring 17.3125" long by 7.3" wide and standing  6.4" high, the attachment was able to take a job up to 5.25" long and 3" in diameter. Fitted with a built-in 1/60 h.p. 115 volt motor running at 1725 r.p.m. and a sealed-for-life spindle running in ball bearings, the device allowed work to be mounted between its centres and ground by the surface grinder wheel. In order to multiply the wheel speed for small-diameter work the surface grinder wheel revolved in one direction while that on the unit revolved in the other. Having ground the part the unit then allowed the job to be indexed, without backlash (the drive dogs could be adjusted to lock onto the work), so that flats or slots, etc., could be formed as required. Should work not ground between centres have required indexing, a collet chuck with a screwed nose-piece compression ring and a set of 13 dead-length collets from 1/8" to 1/2" in 32nd steps was available as a complete set in a fitted wooden box. Able to be tilted, the accessory could be used to grind angles on such items as Morse and other centres and double-cone shafts, etc..