In the West, the improvements in the lathe appear to have resulted from the adoption of a different method of rotating the work; probably arising from the European habit of selecting the erect posture for the generality of mechanical operations. The centers were raised in height, while the bow would appear to have been discarded, one end of the string was attached to a pole or spring above the lathe, while the other was formed into a stirrup or attached to a treadle to be moved by the foot below the work. This exchange largely increased the power of rotation and left both hands at liberty for the management of the tool.
The wooden pole or spring was made from a straight bough or was cut out of some elastic wood, and pared down to a taper form ; from which strip of wood or lath, the word lathe is considered to have arisen. The Greek, Latin and continental names for the machine, are all derived from the verb to turn, and with us one variety is called a "turn" or "turn-bench ; "but the most common appellation among ourselves is that of lathe, and the word appears peculiar to the English language.
The earliest representation of the pole lathe with which the author is acquainted, fig. 19, is copied from a wood-cut in the "Panoplia Omnium," a work by Hartman Schopper, published at Frankfort-on-the-Main, 1568. This rare old book contains 154 engravings of different trades each accompanied by descriptive Latin verses ; the tool grinder from the same collection has been also given in fac-simile page 1129, Vol. III. The following, of which a liberal translation is ventured, accompany the illustration of the turner:-
SeJulus e flaua tornarius omnia buxo,
Torno meo torno, quicquid habere voles.
Pyxidas innumeros hominum formamus in usus,
Immensa quae non utilitate carent.
In quibus abscondens rerum tibi mille colores,
Clam penitus serues, nobile quicquid amas.
Hic pila conficitur, mirag volubilis arte,
Huc illuc baculis fortibus icta salit.
Hie nec abest pueris, qui concitat acrius iram,
Verbere quern verses per sola plana, trochus.
A turner I : - with unremitting skill,
I turn from yellow box, whate'er you will :
Boxes of shapes unnumbered we produce
And who can tell our boxes' varied use;
There may'st thou store, secure from stranger's view,
Thy noble treasures of the brightest hue.
There too the ball is made, which - wondrous sight!
Struck by the wand, rebounds in varied flight.
Here too the top, that warms the schoolboy's force,
And whirls on level ground its well urged course.
The mechanism of this lathe is tolerably apparent; the end of the pole is inserted in the wall and rests loosely upon a joist stretching across the shop, that it may be shifted to different parts of the work as occasion may require. The operator stands, but rests his body against a back rail or rest attached to the lathe.
Jacques Besson, in his work, "Theatruni Instrumentarum et Machinarum," 1569, figured three very curious lathes in which the pole, the archery bow, cords and weights, are all more or less employed in producing the reciprocal motion in the machines. One of these lathes which is described and drawn page 616, Vol. II., is intended for screw cutting.
The pole lathe fig. 20, is taken from the rough illustration but careful description, found in the work of our countryman Joseph Moxon, "Mechanick Exercises or the Doctrine of Handyworks." London. 1703. and is offered for its clear explanation of details, which may prove of interest. One screw and one fixed center are carried by massive wooden blocks or popit heads, the lower ends of which are reduced to pass between the sides of the beds, for their attachment by means of large wooden wedges through mortised holes. The wooden beds are formed of two strong beams, which, with the framing generally, are halved and bolted together. The support of the tool is a stiff bar of wood carried against the side of the popit heads, but capable of being placed at varying distances from the axis.
The pole or spring is fixed horizontally overhead, and rests on a beam by about the center of its length; the butt end being pierced by a hole to work on a vertical pin, as on a hinge, that the other extremity may be placed at any required position above the work. The cord from the pole was wrapped once or twice around the work and then descended to the raised end of the treadle, a wooden rod, the other end of which was hinged to the floor by a piece of leather. The treadle has a similar piece attached to it for the foot called the "cross treadle;" these two pieces being joined by a pin and having several holes for their adjustment to each other. When the workroom was of insufficient height to allow the pole to be used in its ordinary position, the latter was fixed vertically at a little distance from the lathe, and the cord was led from it around a pulley attached to the ceiling and then around the work to the treadle.
Moxon recommends strength in the parts of the lathe, pointing out that a strong lathe may be used for light works, but that a slight lathe cannot be employed for heavy works, while he enlarges upon the inconveniences arising from want of stability. He describes the turner as preferring to support his work, for similar reasons, at no greater elevation above the bed than necessary; and mentions that it was customary for the lathe to be provided with several pairs of popits of different heights, for works of various diameters. The cord or string as at present, was of catgut, and the surplus quantity was wound around the end of the pole, to be unwound for use upon work of large diameter. A description of the archery bow applied to lathes and the hand bow for small works then follows.