Although Publicised for a short time in the early 1920s, the Fulswyng was marketed, if not actually manufactured, by Irwin & Jones of 4, Westmoreland Buildings, Aldergate Street, London, E.C.1. This company were also responsible for the simple little David plain-turning lathe, a 21/2" x 6" machine which, at £3 : 17s : 6d for the bench model, was aimed at the impecunious amateur. Priced at a considerable £31 in bench form (or £39 : 10S : 0d on a treadle and flywheel stand) the backgeared and screwcutting Fulswyng was unusual in having its carriage running not on top of the bed, but on ways formed as extensions to the front and back faces - rather in the manner of the later (and very different) Schaublin precision 102-VM . The aim of the design was to provide a completely free top surface so that the tailstock, running on bevelled-edged ways just like those found on precision bench lathes*, could be brought right up to the spindle nose to allow very short work to be supported at both ends. This idea was not new and other, earlier lathes that allowed a similar arrangement included the well-known American Rivett 8-inch Precision and 608, the very rare Pierce, the equally elusive Wade "Front Way" and the more common English Spencer
Appearing for first time in the Model Engineer Magazine on page 333 of Vol. XL111 in October 1920, the original Fulswyng was obviously in an under-developed state and may have been a prototype. However, by November 1922 the lathe was reported to have been extensively modified with improvements including a much strengthened bed, especially in the region of the gap (as well as along its underside) together with altered feet. However, although when viewed from above the width of the bed was considerable, in side elevation is was still very shallow. Other modifications involved a centre height raised from the original 31/2" to 33/4", a leadscrew of increased diameter and the half-nut engagement lever moved from the headstock side of the half-nut support casting (where it must have been awkward to reach) to the face at the tailstock end.
In order to slide on ways fitted to the front and back faces of the bed, the saddle had, of course, to run under the bed (again, just like the Schaublin 102-VM) with, fitted at front and rear, T-slotted slides, both travelling on V-edged ways. While the front slide was driven in the usual way by a feed screw (that lacked a micrometer dial) the one at the back could only be slid by hand -  a Tommy bar being provided for the operator to lock it in the required position. Using both front and rear boring tables together it would have been possible to set up a job of impressive size for either face milling - using a cutter held in a chuck - or line boring between centres.
Running beneath the bed, down its centre line, the leadscrew was grasped by split nuts positioned immediately below the toolpost, thus obtaining the shortest possible path - and minimum leverage -  between leadscrew and cutting tool. As no rack-drive was fitted, in order to move the carriage by hand, the leadscrew was fitted with a generously large handle at the tailstock end. Screwcutting was by a train of conventional changewheels (a set of 15 may have been provided) carried in a single-slot bracket with the drive passing through tumble-reverse mechanism.
Of the simplest kind, the top slide had V-edged ways, a single triangular tool clamp and a central feed screw -  through this was left exposed to swarf and dirt. As front and rear slides were the same, it was possible to transfer the top slide to the rear section and so use it, for example, to carry an inverted tool to help with parting off.
Described as now well up to the standards of design as to strength the first type must have been relatively flimsy, though both retained vestiges of Victorian engineering in the use of a spindle end-thrust plate carried on two studs outboard of the left hand face.
Backgear was the full-width type, carried on an eccentric shaft to the rear of the headstock and rotated into engagement by a rarely-seen mechanism, a lever fitted with a spring-loaded indexing plunger that dropped into one of two holes bored in the shaft's left-hand support bracket.
One can hardly imagine an example of the Fulswyng has survived, but if you have one the writer would be very interested to hear about it..
*Including: American Watch Tool Company, Arrow, B.C.Ames, Bausch & Lomb, Benson, Boley, Bottum, Boxford, B.W.C., Carstens, Cataract, Cromwell, Crystal Lakes, CVA, Derbyshire, Elgin, Hardinge, Hjorth, Juvenia, Karger, Leinen, Levin, Lorch, Mikron, W.H.Nichols, Potter, Pratt & Whitney, Rambold, Rebmann, Remington, Rivett, Saupe, Schaublin, See (FSB), Sloan & Chace, Smart & Brown, T & L.M., U.N.D., Van Norman, Wade, Waltham Machine Works, Weisser, Wolf Jahn and (though now very rare), Frederick Pearce, Ballou & Whitcombe, Sawyer Watch Tool Co., Engineering Appliances, Fenn-Sadler and the "Cosa Corporation of New York."