Although there are various designs of watchmakers' lathe, some dating back to the late 1700s and including specialised models - for example "fiddle" lathes, "steel turns", Jacot, Swiss, Swiss Universal (also called the English Mandrel) Bottum and Dracip - more modern examples can generally be divided into two types: the lighter "Geneva" and heavier "WW". The "Geneva" can be recognised by a round bed, with a flat machined along either the top (or, more commonly, the back) for its full length and nearly always supported on a single foot. These lathes, invented in 1859 by Charles S. Moseley in the U.S.A., generally took 6 mm or 8 mm collet and were designed only for lighter, very high-precision work. However, the "WW" (Webster-Whitcombe), is by far the more popular and versatile machine (and also of American origin) dating from around 1889. The centre height of the WW was usually 50 mm, though very occasionally 65, 70 mm and other figures are encountered. Of heavy construction, the bed was formed with a 37 mm-wide flat on the top and a 60-degree bevel along each edge, and carried a headstock spindle to accept 8, 10 mm or 12 mm collets.
Exception to the above rules also include a range of fine Boley lathes manufactured from the middle to late 1800s with either a triangular-form bed or an oddly compromise design (which did not catch on) where the bottom of the bed was semi-circular in form and the top triangulated or "bevelled"
Larger than the WW type are what might be called "toolmakers' or "bench precision" lathes: these vary in size from the Schaublin 65 and 70 (the latter being the most popular and frequently-encountered machine in the professional watchmaker's workshop) to larger examples such as the Schaublin 102, 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, 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." While useful machines in a precision workshop, these are outside the scope of this article but further information can be found here.
There were dozens of brands of watchmakers' lathes and a lot of "badge engineering" went on. This was compounded by accessories being interchangeable between makes - so it is entirely possible that a lathe has been "made up" from others either casually over many years of ownership or unscrupulously by a dealer. However, it's very unlikely that the bed, headstock and tailstock will be from different manufacturers; if they are, be wary.
Below is a set of links in the Machine Tool Archive to some makers of watch and instrument makers' lathes and their accessories - some rather common, such as G.Boley, and others very rare - like the O.W.T.
http://www.lathes.co.uk/american watch tool comany
……….. and others here
Manufacturers and Brands
Genuinely high-quality Watchmakers' lathes were manufactured and branded by, amongst others:
American Watch Company (C. S. Moseley-designed lathe circa 1859)
American Watch Company (A. Webster-designed lathe circa 1859/60)
American Watch Tool Company (Webster-Whiitcomb improved-design lathe of 1889 - the WW model)
Boston Watch Company (C. S. Moseley-designed lathe circa 1858)
E.H.J. (E. H. Jones machinery dealers and commissioners)
Faneuil Watch Tool Co
Gem (Gem Glorious)
Gentil (Star Lathes, Switzerland)
George Adams (re-branded Boley and Lorch, etc. and cheaper imitations under his own label)
Hammel, Riglander & Co.
Hopkins (Van Norman)
Jones (J & T Jones UK)
Gustav Klett (East Germany)
Lancaster Special (by the Faneuil Watch Tool Company circa 1899 for sale by a jewellers' supply house L. C. Reisner of Lancaster, Pennsylvania.
Lanco (Lane Cove)
Lorch (Lorch Schmidt)
O.W.T. (Ohio Watch Tool Co.)
Picard (Henri Picard et Frere)
Rivett (sometimes marked Rivett Lathe Mfg. Co. and, possibly, Rivett Lathe & Grinder Co.)
Rivett Lathe & Grinder Corporation Type 1R
ROFB (Royal Ordnance Factory Birmingham)
Scomea (Société Commerciale d'Outillage et de Mécanique d'Aviation)
Sloan & Chace
Star (R. Gentil & Co. Company of La Brevine in Switzerland)
Van Norman (sometimes branded Hopkins)