was not yet. Improvements were being made constantly 

 both in the carving-machines themselves and in the 

 methods of using them, until these machines were 

 able to produce work of such perfection that even the 

 finishing touches of the hand-carver were unnecessary. 

 And presently, these machines were so improved and 

 made in such a manner that instead of turning out a 

 single piece of carving at one time half a dozen or more 

 J : '.plicate carved pieces could be made by the workman 

 at one time. 



The principle on which these machines work is 

 that of the familiar drawing implement, the panto- 

 graph. In this instrument, two arms are arranged so 

 that the drawing-points upon them move always in 

 parallel directions and at equal distances. By this ar- 

 rangement it is possible to draw two exactly duplicate 

 pictures at the same time, or to copy a picture already 

 made by passing one of the points over the outline of 

 such a picture, while the other marks on a separate 

 sheet. In this simple copying pantograph no pro- 

 vision is made for the points moving in a vertical 

 direction, only a lateral movement being necessary. 

 But by adopting the same principle and having two 

 points always at exactly the same relative distance 

 from each other, vertical as well as horizontal dupli- 

 cate movements in any direction may be made. 



This was the principle now adopted in these dupli- 

 cating carving machines, where six, eight, or even a 

 dozen whirling chisels, arranged one above the other 

 in a vertical frame, all act in unison, following exactly 

 the movements of the pilot implement guided by the 



[220] 



