APPENDIX. ] DRA WINGS FOR PHO TO-ENGRA VING. 2 1 9 



R. be /.. g. t. Filame7tt of Necturus C. Leucocytes, 



For y% reduction the following are large enough, 



Mcten. mtc. mtp. mtpr. 1 2 3 4. 5. 



It is convenient to have the complete alphabet both in capitals and small letters 

 and series of numbers in different sizes. The printing should be done on firm, but 

 light weight, white paper (20 lb. Demy has been found satisfactory). 



The slips thus printed are pinned upon a board and coated upon the back with 

 liquid gelatin ($ 311 ) and dried. With fine scissors the words are cut out neatly, 

 moistened and with fine forceps placed upon the drawing and pressed down with 

 blotting paper. Upon a large and complicated plate, the letters and words should 

 be placed so as not to offend the eye. Those which are intended to be parallel to 

 each other and to an edge of the plate should be strictly so, as determined in ad- 

 justing them by means of the T-square. The numbers of the different figures of 

 a plate can be arranged so as to lend to the general harmony and still be kept 

 close to the designated figure. If a great deal of lettering and numbering is ap- 

 plied a careful plan of the exact place of each word must be determined before 

 any are fastened, otherwise confusion results. A word may be made to follow the 

 arc of a circle, by snipping the slip 011 which it is printed with the scissors and 

 curving it after it is moistened. 



\ 36S. After the letters and words are thus fastened, if any of them are not 

 exactly upon the parts to which they refer, a line from the part to the word should 

 be drawn with the right line pen and T-square. Dotted or full lines may be used, 

 according to which will show most clearly — and in passing over a deep shadow, 

 it may be scratched out with a sharp scalpel, leaving a white line. 



I 369. After and only after every part of the drawing is as complete as possible 

 should the eraser be lightly used to remove pencil marks and the sharply pointed 

 knife or scalpel to remove slight defects, as the overrunning of an inked line or to 

 pick out shadows which are too deep. This is to avoid roughening the surface of 

 the drawing paper and thus making it impossible to add clear cut lines with the 

 pen. 



§ 370. Considerable modification of a photo-engraving can be made by a skillful 

 engraver with his tools. Most of the illustrations of the current magazines are 

 half tone or photo-engravings retouched by the engraver. Slight defects of a plate, 

 a line a trifle too long, a complete line which should be interrupted, a superfluous 

 line can be easily remedied, but a line cannot easily be added. A deep shadow 

 can be lightened or removed, but it is cheaper to renew the drawing than to under- 

 take extensive changes in the plate. In the case of a plate made up of drawings 

 on separate papers, the edge of each paper casts a shadow which would appear in 

 the plate except that it is cut out by the photo-engraver, and in the same way the 

 edges of the slips used for lettering cast shadows which the engraver removes. If 

 any such lines should appear in the proof they can be indicated and removed be- 

 fore used in printing. 



