Referring to the enlarged section Fig. 6. there will he seen under the wheel \VW, two conic frustums, the in side one of which is fixed to, and forms one piece with, the wheel, and the exterior one is attached to the timber frame above, and serves as a socket for the inside cone to turn in, and which thereby preserves the spindle steady as it re volves. The interior of the interior cone has on one side what the workmen call a feather, and which slides freely in a groove in the spindle, so that the former cannot re volve without carrying the latter with it : at the same time the cone and spindle being free in their motion up and down, the latter may be raised while the machine is in motion, without lifting the wheel, and consequently with out throwing the work out of geer. The groove in the spindle is shown at g g, the sections being made to pass through it.
The other part of the wheel-work, and the method of throwing the wheel out and into geer, differs in no respect from common mill-work, and therefore requires no par ticular description.
Method of attaching the Timber to the Carriage, and the Carriage to the endless Chain.—In Fig. 7. is shown a sec tion of the carriage enlarged, passing through one of the transverse screws, of which there are seven seen in each carriage of the plan, Fig. 2. In this figure a a is the ma sonry, to which are fixed by screw-bolts and nuts the sliders DIM. LE are the sides of the carriage, which are strength ened at intervals by cross pieces; one of which, F, is seen in the figure ; KK are pieces of iron, shown also in Figs. 8. and 9. fixed to the timber of the carriage, and serving to guide it along on the sliders, and to prevent it from com ing off. The upper part K is furnished with a row of flat teeth ; and pieces of iron of a similar make are seen at a and b. The piece a has an interior screw, in which works the exterior screw C c, running in a collar at C, so that by turning this screw by a wrench for the purpose, the piece a is drawn up towards C, and presses the timber, when this is of sufficient breadth, against the flat teeth in K, and thereby holds it fast. But when the breadth is not equal
to this, then an intermediate piece of timber ft is introduc ed, and the flat-toothed piece b is screwed into a slider, and the whole brought up together by the screw C, as be fore.
To attach or detach the carriage to or from the endless chain, a clip Q L is fixed to the cross-piece F ; Q being wholly a fixture, but the other piece L capable of motion ; into this passes the screw, whose end is seen at K, and by means of which the jaws LM may be opened or shut at pleasure : when open, the chain passes between them, and the carriage remains at rest ; but when they are shut close, they catch the chain, and the carriage then partakes of its motion. Fig. 10. shows the method of fixing the gouges to the rim of the wheel ; and Fig. 12. is the wheel itself to the same scale as the transverse section ; Fig. 6. and Fig.
11. shows the system of wheels at the end A of the plan, Fig. 2. also on an enlarged scale. The line and weight np z, and W are attached to a plane wheel, under the large wheel so, its purpose is to regulate the motion of the car riages ; for when their motion coincides with that of the re volving cutters, the action of the latter has a tendency to urge the carriage along too quick, and when it returns the motion is too slow ; the line therefore which is attach ed to the circumference, serves by its weight to retard the motion of the carriage in the former case, and to accele rate it in the latter. During the late war, when there was great demand for gun-carriages, this fine machine was kept in constant employment, and both carriages were in perpetual action ; it is now but seldom in operation, and never with more than one carriage going at a time.