There can be few precision machine tools that have had such a long and uninterrupted production life as the Webster-Whitcomb (WW) lathe. From 1889 the WW was made (first) by the American Watch and Tool Company (eventually under the supervision of F.W.Derbyshire as chief Superintendent) then by Derbyshire himself when he formed his own company - and subsequently by succeeding generations of his family until it became a 'Special Order Item' in 1990.
The foundation of this remarkable lathe's success lay in the invention around 1857 (by the American Charles Moseley) of the "split-chuck" - or collet as it has come to be called; this breakthrough in design, combined with a hollow spindle and eventual adoption of a hollow, threaded draw-tube down which material could be passed - rather than the original solid draw-bar - completely revolutionised the concept of the watchmaker's lathe. "Chucks" could be produced in a myriad of different forms and sizes, able to hold almost anything the watchmaker or repairer wished to machine, they could be of the most microscopic bore, or made in the form of hollow or conical discs with multiple steps cut in them to hold items of a larger diameter. They were also able to carry conventional 3 and 4-jaw chucks and large faceplates - whilst the inherent versatility of the concept led to the production of many different types and special forms, each designed to assist the watchmaker in some specific task - Balance, Cement & Wax, Screw-finishing, Jewelling, Jumbo, Bell, Taper, Wood screw, False-nose (buff ), Stone-setting and Arbor, for example; however, given a chuck with a blank end, the watchmaker was often able to aviod buying a specially made unit and construct a holding device to suit his own particular requirements. 
The WW lathe was not, however, a success because of its spindle fitting - that was already in use on many other lathes - but because Ambrose Webster designed a headstock, spindle and bearing assembly where the relative proportions, and hardness of the materials, allowed chucks to be used so much more accurately. In addition the lathe was not only exquisitely made, from high-quality materials, but had that perfect 'look and feel' which came from the designer's close attention to every facet of its form, mechanical and cosmetic finishes - and method of manufacture. The bed, unlike the round Swiss 'Geneva' pattern favoured by European makers, provided a perfectly flat surface with bevelled edges upon which it was easy to engineer the secure mounting of a variety of useful accessories..