While all ornamental turning lathes from Victorian times are uncommon, those by J.Munro of London must rank as one of the least likely to be found. Even more difficult is to discover much about their maker - either Munro Senior or his more gifted son - the latter having a considerable standing within the precision machine tool industry of the mid 19th century gauged by three references to him in a series of papers gathered together and published in a magazine "The English Mechanic" during 1868 - though with a confused heading stating: "The Lathe and its Uses ?in which is described an entirely novel form of lathe for eccentric and rose engine turning ?a lathe and planing machine combined ?and other Valuable Matter relating to the Art. Copiously illustrated. New York. John Wiley & Son, No. 2 Clinton Place."
Notes about Munro include:
The pitch of the screws must be not only fine, but even and regular, and the screw itself of precisely the same diameter from end to end, else it will work loosely through its nut in one place, and jamb in another. It is extremely pleasant to feel the exquisite smoothness and oiliness, for no other word will express it, of the movements of sliding parts in the workmanship of Munro or Holtzapffel, especially if compared with inferior work.
It would be better for the amateur to get the screw and nut cut by Holtzapffel, Munro, or other first-class maker, who has the requisite means ?
In a later page will be found a drawing and description of a new device of the kind - a planing machine, devised by an ingenious and first-class maker, Munro, of Lambeth, and patented by him.
Munro had a connection with the far better-known Holtzapffel lathe company, where he is thought to have been employed in a senior capacity, and his machines enjoyed a similar quality of design and manufacture. However, although workmanlike, the various castings of the Munro appears to have lacked the fine cosmetic finish found on the more expensive models in the Holtzapffel range - as well as those by other contemporary makers including Goyen and another London-based engineer, Muckle. Also missing (at least on the example shown below) was any method of mounting an "overhead" to drive toolpost-mounted milling and drilling spindles, a feature usually considered essential to the class of lathe. Unfortunately, it's not known if any Munro lathes survive with the many complex accessories required for ornamental turning and, if so, what form they might have taken. Could they have been as finely-engineered as these?
Using a relatively long bed with ways formed by inverted Vs running along its outer edges, Munro's lathe incorporated a number of unusual features, including a very large and elegant "gut-drive" headstock pulley in bronze, its largest diameter having its front face drilled with the usual circles of diving holes and the three other sizes carried, to its rear, on six spokes. Spindle thrust was taken against a screw adjustment fitted to an outboard plate that, instead of being close to the left-hand bearing as might have been expected, was carried on a pair of long, slender extension arms screwed to the outside faces of the bearing housing. However, the headstock casting was also formed with a pair of bosses that could have been machined to fit a more conventional arrangement - and so the fitting used would almost certainly have been to allow the fitting of one or more accessories. As the long, outboard end of the spindle was fitted with a tapered bronze sleeve and its end threaded, might it have been designed to carry a chase-screwcutting attachment or, as used for example on the Muckle, a "sliding spindle" arrangement? Certainly, the length of the spindle extension would have made a sliding screwcutting set-up possible - the design principle is explained here. It is also possible, though less likely, that other accessories could have been mounted, perhaps a sawbench, shaper or milling attachment - the latter available on a number of "precision bench" lathes in the late 1800s including those by the American makers Van Normanand Stark..
Drive came from a treadle mechanism, the forged crank turned by use of a full-width foot-plate and the single, slender (rather light-looking) flywheel incorporating four pulleys of widely-different diameters - this arrangement being in contrast to the more common one of two, three or more, little different in size, spaced together on the periphery and, much closer to the centre of the wheel, one or more much smaller to generate low speeds.
A conventional-for-the-time slide-rest was fitted with the unprotected, fine-thread feed screws formed with square ends to take crank handles. The screws, unlike the right-handed ones on many other lathes of the era that gave what was called a "cack-handed" feed, were left-handed to give a proper "turn-the-handle-right-and-the-slide-moves-inwards feed". The semi-circular front edge of the swivelling top slide was fitted with a bolt-on bronze ring engraved with degree markings and each side of the cross slide fitted with cosmetic covers - in bronze, naturally. The top slide had no provision to take a turning tool, only a hand T-rest - though presumably the maker would have offered alternative fittings if the full potential of the lathe was to be realised.
If you have a J.Munro lathe (or other ornamental lathe that you would like to see featured in the Archive) the writer would be most interested to hear about it..