374 DRAWING FOR PUBLICATION [Cn. X 



projected again upon the surface to make sure that all the details 

 have been correctly drawn. 



It is always desirable that drawings accompanying a scientific 

 article should be at a definite enlargement or reduction, and that 

 the scale of the drawing be definitely stated (See Style Brief, of the 

 Wistar Institute, pp. 16-17). 



If the drawings have been made without first doing this, then 

 the magnification can be found by arranging the apparatus exactly 

 as when the drawings were made and using a micrometer as directed 

 in 508. 



A plan frequently followed is to have a few lines of the microme- 

 ter image drawn in one corner near the picture. Then any one 

 can determine the scale of magnification or reduction ( 510, sioa). 



528, Lettering the drawings. After the drawings are finished 

 the various parts can be lettered, or words can be written in where 

 needed. Most workers, however, cannot letter neatly enough for 

 publication. For such it is better to use printed words, letters or 

 numerals. 



It is assumed here that the drawings will be reproduced by some 

 photo-engraving process ; and for this the letters or words pasted 

 on the drawing would best be printed on tissue paper, ( 528a); 

 Gothic type is best. By consulting fig. 216, one can select the 

 proper size for the reduction to be made ( 531). 



527a. Tracing pictures natural size on drawing paper. It frequently 

 happens in making the drawings for a book or for a scientific paper that pic- 

 tures from other books or scientific papers are desired. Of course, if there are 

 to be no modifications, the simplest method is to borrow an electrotype or to 

 have the photo-engraver make a new cut; but sometimes only an outline is 

 needed or modifications are desired. 



If the picture is to be the same size as the one in the book or periodical it 

 can be easily traced upon the drawing paper as follows: In place of a wooden 

 shelf on the table (fig. 183, 460) a piece of thick glass is placed on the brackets 

 and an incandescent lamp of 40 or 60 watts, surrounded by a lamp shade of 

 some kind, is turned so that it shines directly upward. It is then placed up 

 close to the glass and the picture to be traced is placed on the glass, and over 

 it the drawing paper. The light is so strong that it traverses the picture and 

 the drawing paper and the picture is clearly seen on the upper side of the 

 drawing paper. It can be traced almost as easily as if an image were projected 

 upon the upper face. In tracing drawings for this book, Wattman's hot pressed 

 paper and Reynold's bristolboard were used in making tracings in the way just 

 described. Even if there is print on the opposite side of the page the tracing 

 of the picture can be made successfully. 



