SCIENCE IN THE INDUSTRIAL WORLD 



another as the keys are struck, and also a paper scale 

 for registering the body-size of the type. 



"Before beginning his task, the keyboard operator 

 sets an index of the number of ems required per line. 

 Each stroke of a key perforates the paper ribbon in 

 such a combination as to control the matrix of the 

 proper letter in the casting machine, and causes the 

 registering scale to charge to the line an amount equal 

 to the body-width of the type just selected. In this 

 way a line of matter is progressively perforated and 

 charged until, as the end is approached, the line- 

 scale shows that the next word or syllable cannot go 

 into that line, while another portion of the registering 

 scale indicates the amount of unfilled space in the 

 line just perforated if it should be cast with its spaces 

 of normal body size. Still another portion of the scale 

 has been keeping account of the number of spaces 

 used between words of the line, which may be varied 

 in the process of justification. The machine thus 

 mechanically notes for the operator the amount of 

 space to be added, and the number of space-types 

 among which the variation from the normal body- 

 width may be apportioned. At the completion of 

 each line the operator, by merely noticing the figures 

 shown by the pointer on the justifying scale, knows at 

 once what additional holes to perforate in the record 

 in order to secure perfect justification. When he 

 has touched the justifying keys the registering scale 

 points to zero, advancing again as the new line 

 progresses. These operators are all automatic. 



"From the perforator the spool passes to the casting 

 [146] 



