Almost entirely divorced from the development of industrial-sized machine tools the evolution of small, high-precision watchmaking lathes took some interesting turns - including the dead-end "Swiss Universal" and "English Mandrel" (an interchangeable term) a design introduced during the early 1800s. Shown below is a typical example (now considered a highly collectable object d'art), in early and later version as made by G.Ve Vauscher Jeanneret Fleurier. A machine usually found with its headstock and bed cut from one piece of a bronze alloy - and of rather short and slender proportions - the spindle was supported in a single bearing at the front and against a hardened centre at the rear. Such a simple but effective arrangement reflected contemporary small-lathe practice for much of the 1800s as typified by, for example, by some versions of the Pfeil. To make the machine as compact as possible, and free it from the complications of a separate and complex rope-driven countershaft, the lathe was equipped with an integral drive system - probably the world's first - where the spindle was turned by a hand-operated crank working through step-up ratio, spiral-form gears. However, in every case the drive gear was bolted on and could be removed if required - provision for an alternative belt system often being included (or able to be subsequently added by owners). However, some examples of a rather more complex design, with part-bronze-part-steel construction, have been also been found with a neat, hand-powered round-rope drive that was turned through 90-degrees to wrap around a pulley on the spindle centre line - the pulley then acting as a catchplate to turn the spindle through a drive dog. Yet others versions, with the rim of the faceplate turned to accept a rope drive, also exist - though this would have required the use of a separate countershaft and its associated complications of drive and mounting. Another of the lathe's significant features was the inclusion of a decent compound slide rest that allowed the operator precise control of the cutting tool. In many cases these lathes had what appeared to be three slide rests like, for example, the later American Derbyshire lathes. However, on the Swiss lathes this fitting was not a slide but a very clever means of means of adjusting the tool height The action depended upon two pairs of opposing wedges that, when moved towards each other lifted the tool and when moved away lowered it (it being necessary to slacken the top clamping screw first). The wedges were shifted by two round bars, pushed by a plate under a screw action, with their inside (hidden) section formed with wedge faces - each facing in opposite directions, of course. As was universal at the time, a hand T-rest was also provided, mounted on its own separate and adjustable bed rest.
Of a type sometimes referred to as a "mandrel", the "faceplate" was of a type that remains in production to this day for use on watch and clockmakers' lathes. Three radial slots each carried a split clamp with a fine-pitch screw (for precise adjustment) with the centre on some examples carrying what was to become known as a "pump centre" where a work-piece, with a true hole through it, could be exactly centred by using the pointed end of a spring-loaded rod.
Although, on its introduction, the Swiss Universal had been an entirely novel concept (and for its intended purpose, a very useful machine) some serious drawbacks were its relatively slow speed (a considerable handicap when working on small diameters), the inability to hold small workpieces on their outside diameter and a lack of rigidity in the bed. In all these respects it was eventually to be rendered obsolete by a number of significant and closely overlapping developments instigated by a close-knit group of Americans. Starting in 1857 or 1858 the first improvement came with the invention by Charles S. Moseley of a small bar-bed lathe with a hollow headstock spindle that could accepted "split chucks" (or "collets" as they are now known) - a machine that was the immediate forerunner of today's "Geneva" lathes. In 1862 came the introduction of the high-speed headstock with a hardened steel spindle running in glass-hard and lapped steel bearings (an important development next incorporated in the larger "bench precision"* lathes by John Stark during the same year, a type that was to make miniature precision work of all kinds so much easier). In the early 1870s Ballou, Whitcomb & Co. introduced the next significant advance, an improved version of a lathe built originally by A. Webster of the American Watch Company and then independently manufactured by two former employees, Kidder and Adams. By 1879 Weber and Whitcomb had combined to form the American Watch Tool Company and by 1888-9 were ready to market the final and definitive form of heavy-duty watchmakers' lathe - the 50 mm centre height Webster-Whitcomb, or "WW" as it was to become better known. With a spindle and bearings constructed from the very finest grades of hardened, ground and lapped steel (and able to run reliable at high speeds for years on end) draw-tube closed collets and a rigid, absolutely accurate bevelled-edge bed that ensured precise alignment of headstock, slide rest and tailstock - this seminal lathe finally answered all the needs of any craftsman engaged in watch and instrument manufacture or repair.
If you have a Swiss mandrel lathe of this type the writer would be interested to hear from you. Photographic essay continued here and here
*Eventually to be made by many other firms 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, Perrenoud, 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."