METHODS OF RESEARCH.' DRAWINGS 129 



For ordinary pen-and-ink or wash-drawings we generally use 

 Reynolds' English Bristol board and Higgins' water-proof 

 India ink. 



The first essential of a good drawing, and the sine qua non, 

 is fidelity, but one may have kept that and yet the drawing may 

 be unattractive, i.e., all black or all pale. Generally I prefer 

 to indicate certain tissues by shading them and I select these 

 arbitrarily in such a way as to give to the drawing a varied and 

 pleasing effect. This is gratis! 



When letters or figures are introduced into photographs or 

 drawings the intended reduction should always be taken into ac- 

 count, i.e., the letters and figures must be large enough so that 

 they may not be lost or obscured when reduced, since much 

 time is sometimes wasted in trying to read an author's references. 

 For the same reason, when drawings numbered serially are cut 

 apart and rearranged on a plate, as sometimes happens in an 

 effort to economize space, they should be renumbered serially 

 from left to right and top to bottom. This is laborious to the 

 author, but the labor involved is as nothing compared to the 

 burden the neglect of it throws upon a thousand readers, par- 

 ticularly if the figures are numerous and the lettering indistinct. 



Paintings. Water-color drawings are often indispensable, 

 since neither photographs nor ordinary pen or pencil drawings 

 can convey color effects satisfactorily. A faint pencil outline 

 is usually sketched in and then the proper colors are flowed 

 over the surface with a swift sure touch. The technic is very 

 different from that of painting in oil, which may be worked over 

 and over, since in a water-color the right pigments must be laid 

 on swiftly once for all, the drawing admitting afterward only 

 of a minimum amount of correction. It is nevertheless greatly 

 to be preferred to oil, because it gives a smoother surface and 

 brighter colors. Not many students will be able to make their 

 own water-color drawings. When such are necessary some one 

 can usually be found to do it. Since such persons are usually 

 untrained, scientifically, in my own case I have always found it 

 necessary to superintend the process, suggesting now and then 

 the colors to be sought for and the details to be emphasized. 

 In this way I have succeeded quite well with various artists 



