Produced in a factory on Newton and Cutter Streets in Waltham, Massachusetts the Waltham Machine Works lathe was the product of a firm famous for both its high-quality engineering and design skills.
Massachusetts was the cradle of not only the American Revolution (and the state where the first shot was fired in the American War of Independence) but also the birthplace of the American Industrial Revolution. The state, having enjoyed a head start in acquiring engineering expertise, was home to many makers of fine-quality machine tools amongst which the better known became Stark, the American Watch Tool Company, B.C. Ames,  Wade and F.W.Derbyshire - who all manufactured precision bench and watchmakers' lathes - Nichols who made milling machines and Rhodes with their convertible shaper/slotter. Waltham was also the birthplace of the well-known Van Norman milling machine and automobile equipment company; founded in 1888 by Charles E. and Fred D.Van Norman as the Waltham Watch Tool Company (to make tools for the watch-making trade) the Van Norman name appears not to have been used on their products until a few years later when they moved to Springfield.
The Waltham Bench lathe, first advertised in 1899, employed a bed with a single large T slot down one side. Being otherwise symmetrical the bed, available in lengths of 32 and 36 inches, could be "turned round" so that the slot faced either to the front or rear; this allowed a wide-range of interesting accessories to be mounted, some of which are illustrated below and on other pages.
The headstock spindle was unusual in that, once the bolt holding the drive pulley had been slackened, it could be withdrawn from the plain, parallel bearings without upsetting their fine adjustment. The spindle bearings were held in split, taper bushings with an adjusting nut acting on the outer bushing; the bearings could therefore be closed down onto the spindle whilst remaining perfectly parallel - the inside faces of these bushes also served as thrust bearings. The English Drummond B Type 3.5" lathe used a similar, if much simpler system, whereby the split spindle bushes were threaded on their outer ends and large slotted brass nuts (pressing against the outer faces of the headstock) drew them into tapered housings machined directly in the headstock casting.
Unusually for a high-class precision bench lathes the largest diameter of the headstock pulley was against the right-hand headstock bearing instead of the smallest - an arrangement possible adopted to allow easier fitting of the optional epicyclic reduction gearing within the pulley.
Two types of compound slide were available, identical in all but the way that they fitted to the bed; the simpler of the two versions registered against the vertical way along the front edge of the bed and was retained permanently to it at right angles; the other was fitted to a graduated base and could be swivelled 45 degrees each way..

A Waltham lathe fitted with changewheel screwcutting with drive to the top slide.
This was a very well engineered accessory; it was mounted by turning the bed round so that the single T slot faced the front and using it to hold two substantial brackets that carried the motion from changewheels to top slide. Unusually, this attachment did not, like the great majority of similar systems, use a universal joint in the drive system. The drive line was completely straight until it arrived at an enclosed gearbox just before the top-slide connection. This gearbox was ingeniously split about its centre line, and one half was able to pivot relative to the other, so accommodating the cross-slide movement that was necessary to position the thread-cutting tool; a glance at the picture above should make the operation of the system clear.
Gears were available to cut any thread between 5 and 100 t.p.i and, if the slide rests were equipped with metric screws, pitches in millimetres between 0.20 and 4.00 could be obtained as well.

Waltham lathe fitted with "Chase" Master-Thread screwcutting.  "Chase" screwcutting was developed by Joseph Nason of New York, who obtained US Patent No. 10,383 on January 3, 1854 for an "arrangement for cutting screws in lathes."
This picture shows clearly  the well-proportioned items used on the Waltham to perform this early type of screwcutting. The bed was turned so that the T slot ran down the back of the bed; in the slot were three adjustable supports two of which carried the Master Thread (also known as a hob or leader) - whilst at the headstock end the third bracket supported an arm that carried additional gearing to extend the threading range.
A "half-nut", held in the base of an adjustable tool-slide, pressed on the thread and transmitted its form to the workpiece. The interconnection of the cutter holder and the half nut allowed the nut to be lifted out of engagement and the cutting tool returned by hand to the start of the thread without stopping or reversing the lathe; a little additional depth of cut could then be applied by the tool slide, the half-nut rested back on the master thread - and the cut restarted.
Whilst this system produced absolutely accurate threads, and was especially suited to delicate operations on thin-wall tubes used to construct such items as microscopes, the length of thread that could be cut, and the number of threads per inch or mm, depended upon the availability of the appropriate thread master.
In order to reduce the spindle speed for screwcutting, or larger faceplate work, Waltham offered a special headstock with a completely enclosed 4 : 1 ratio epicyclic-reduction gear.
A very simple form of this screwcutting mechanism can be seen on the Goodell-Pratt Pages whilst on the Stark,  Pratt & Whitney, Ames,  Potter and Wade pages alternative and more highly developed arrangements of the same system can be seen.

Waltham swivelling compound slide fitted with a "Norman Patent" quick-set toolholder. The hardened toolpost was split on one side and clamped to a robust central post. The tall, knurled screw protruding from the top of the toolpost allowed fine adjustments to be made to the height setting. A similar design was used on the English Drummond M Type lathe. Note the location of the compound slide rest - instead of being bolted down against the bed's bevelled edges it is pulled up against a vertical surface.