740 



CARVING BY MACHINERY 



much facility as if it -were a floating body. Primarily this table has two straight- 

 linod motions at right angles to each other, but by combination of these it may move 

 over any figure in a horizontal plane ; and because this is accomplished without an- 

 gular motion about a centre, every point in the surface of the table moves through the 

 same figure at the same time ; hence the power of producing many copies of a pattern 

 simultaneously. 



The second, or vertical part of the machine, is a cast-iron bridge supported on 

 columns across the centre of the bed plate ; on the centre of this bridge piece is a 

 wide vertical slide, 5, 6, with a (T) slotted bar on its lower edge ; to this bar the man- 

 dril heads or tool holders, 9, 10, 11, are bolted, at such distances apart as suit the 

 width of the work in hand, and in such numbers as it is convenient to work at one time. 

 If the framing of the machine is massive and well fixed, six or eight narrow pieces 

 may be carved at once ; but if the width of the work is equal to half that of the table, 



436 



only one can be done, as in that case half the table is required for the pattern. The 

 motion of the vertical slide is governed by the workman's foot on the treadle, K, Q, s ; 

 at s balance-weights are placed, so as to adjust the force with which the tools will 

 descend on the work ; any pressure on the foot-board R lifts the slide, and with it 

 the tools and tracing point. 



Beturning to the horizontal part of the machine, d, e,f, g, is the pattern or original 

 carving which is to be copied, and h, i,j, Jc, two copies in progress. The movements 

 of the floating table are managed by the workman with the hand-wheels TT, v ; the 

 left hand, on u, directs the lateral motion on the frame, and the right, on v, directs the 

 longitudinal motion on the bed plate ; the left-hand movement is communicated by 

 the cord x, x, which is fixed to brackets w, w, underneath the table, and makes one 

 turn round a small pulley on the axis of the wheel tr. The right-hand movement is 

 communicated by the cord z, which is fastened to each end of the bed plate, and" 

 makes one or two turns round the pulley K. When at work, the man stands inside 



