As pioneers in the business of supplying watchmaker's lathes (and specialized watch-making machinery) Stark can, perhaps, be forgiven for ploughing their own furrow and making most of their lathes incompatible with the established standards of the day - especially the all-conquering WW type. The company also produced many one-off lathes, of a different specification to the ordinary types and fitted with special equipment, yet all based upon standard components and often destined for use in watch-making factories. Not only were Stark accessories not able to be used on other makers' lathes (in comparison to the wide interchangeability of the standard WW type) but the expensive collets were also unique and not transferable either - a factor that must have limited sales to customers with other brands of well-equipped, 8 mm  lathes who would have had to buy entire new stocks from Stark.
Stark watchmakers' lathes were listed by numbers - though one used a single letter - and are known to have included the tiny and rare No. 1, the more common Nos. 2 and 3 and the Model E.
Very early types can be recognised by their distinctive headstock where the rear bearing was carried in what amounted to a swan-neck extension, the whole assembly being held to the bed by a single round nut with a knurled edge. Contemporary  advertisements described these first examples as Stark's New Patent Combination Lathe.  with a note that the patent had been extended from October 19th, 1872 (the original patent having been granted on May 30th, 1865). Of the three models listed, the No. 1 STEEL was the cheapest and sold for $36 (the word Steel indicated that this was a very high-quality machine fitted with a hardened and ground spindle running in honed and glass-hard steel bearings). Its bed was 63/4" long, the headstock had just a single groove in the drive pulley and it came with five split collets and one each of a cement collet, a patent cement, a centre and two "stops". The No. 2 STEEL had a 2-step headstock pulley, a bed 81/2" long, came with the same range of basic equipment as the No. 1 and sold for $39. The No. 3 STEEL  was, in effect, a No. 2 but fitted with a 4-inch diameter faceplate equipped with three adjustable clamps (this being described as a universal head), a 3-step pulley, a screw-driven compound slide assembly  and eleven collets; it sold for then astronomical sum of $120. The second machine shown on this page is a much later, more modern example with a typical WW (Webster Whitcombe) flat-topped, bevelled-edged bed 15.5-inch long and 1.5-inch wide with a central T-slot - and so typical of the design as used by many other makers. The  Model 3 or "E", and the largest or next-to-largest in the range, had a centre height of 65 mm and, apart from its size, appears (with the exception of a few small  refinements) to have been a beautifully-made if conventionally designed type. While many watchmaker-lathe headstocks had two or more rings of indexing holes drilled in the outer face of the headstock pulley (together with a locking arrangement based on a long, flat spring-steel arm pivoting from a point on the headstock) the Stark had just a single ring of holes - though a generous 120 in total. The indexing system was, however, much more rigid than many makes with the spindle held positively by a pin contained within a separate housing screwed to the headstock and able to be positioned at either its front or back. To allow the use of a larger indexing plate (as would commonly have been either screwed to the outer face of the drive pulley or secured on the end of the spindle) an additional mounting point for a conventional spring arm was provided (with a set-screw for retention) on the rear face of the headstock. The collets were the usual Stark specials, sized differently to other makers with a 9.1 mm body diameter (0.305 in.) a length of 1.745", a 20º angle and a 40 t.p.i thread. The "Swing Tailstock" was of a similar design to those used on the larger Stark bench lathes and worked in exactly the same way' the three fingers enabling different dimensions to be used for jewelling without having to reset for each change in diameter.
Though early on the scene, Stark soon met increasing competition and, with many others makers joining the market for watchmaker's lathes, their range of models was never developed beyond the normal for this class of machine. However, with their range of precision bench lathes, and busy making specialized tooling and machinery for factories producing watches and clocks, no doubt their was insufficient capacity or interest to take them any further.
If you have a Stark watchmakers' lathe, the writer would be very interested to hear from you.