SYMBOLIC NOMENCLATURE. 127 



given here, and will omit some of those enumerated. See 

 graphical table of operations, page 133. 



We begin by the simplest way of changing an object, viz., by 

 exposing it to some influence, such as heat, which will change its 

 constitution ; or to some process which will change its condition 

 externally, as by pickling. From this class of operations we 

 pass by slight degrees to those where more active means are 

 employed, as in painting, oiling, etc. To such operations gener- 

 ally we give a series of symbolic numbers, beginning with 101.* 



We now come to more active means of attack, such as those 

 which make a change in the shape of the object. This lot in- 

 cludes generally workers in sheet metal, like tinners, etc. In this 

 I assume a, distinction between a change in shape and a change in 

 form : we have iron, say, in the form of sheets which may be 

 fashioned into a variety of shapes. This group is numbered from 

 20 1 upwards. 



Changes of form are more serious and are effected in two 

 general ways : 



ist. By plastic processes, such as are enumerated in the 

 following list from 301 up. 



2d. By cutting of the various kinds described in groups 400, 

 500, 600, 700. f 



The next step in complexity relates to the means employed to 

 unite component parts together. These are numbered from 80 1 up. 



Then comes the 900 group, relating to unclassified operations. 

 It will be seen that many of these require the highest grade of 

 labor. This resemblance between the grades of labor in the same 

 group is accidental, and though by no means conclusive, is quite 

 reassuring as to the general correctness of the analysis. 



* As a parallel change to that of condition might have been named that of situation, 



comprising the means used to move objects from place to place by hand, by team, by 



power, etc. But as this group of operations would only require four or five out of the 



99 numbers allotted to it, and for other evident reasons, it is placed in the same class 



with others relating to changes of condition. 



t If there were not so many cutting processes to be provided for, it would be more 

 consistent to unite all cutting operations in one group, 400. But as the tendency of 

 machine work seems to lie in this direction, I have left all the room possible for 

 extension. The classification of cutting tools is from Rankine. 



