PERSPECTIVE DRaWxNG. S. 



Case there will be no necessity to take off the burrs, as the en- 

 gravers call the ridges raised in ploughing copper; and, from 

 this plate, feii thousund impressions may be taken of the faint 

 lines, by way of guide, on the drawing-book of a young begin- 

 ner, without injuring the plate; for I can assure your readers, Utility of en- 

 that it is more difficult to erase a slight scratch from ^ sharp ^j^^^^^^^^^^^^^j^^ 

 needle on copper, by the act of taking impressions, than the 

 deepest cut of the graver ; the reason of which is, that the 

 ridges of the skin of the printer's hand can never enter that fine 

 line, whereas, in a coarse one, he polishes the edges of it down 

 by. every operation, and thus renders it a smooth channel, at 

 last undefined, and incapable of retaining the printing ink ; 

 and the reason I am so diflfuse on the subject is, that I tliink the 

 -knowledge of it may be generally useful, particularly to those — particularly 

 who wish to extend the publication of botanical outlines: as it "^ ° "^* 

 is not necessary to be taught the art of engraving for those who 

 can draw lines; to design on copper the peculiarities of plants, 

 or their anatomy. How to trace deeper lines with certainty on 

 copper as easily as on paper, I will have the pleasure to com- 

 municate to you at my next leisure moment. 

 . But, to return to our subject. 



To this siinple contrivance, we may add a sheet of perpeii- Sheet for per- 

 dicular lines, by which means the uprights will all be shewn ; pe^^icular 

 and for very heavy intellects, at first even the horizontal scale ' 

 might be useful, though I never found it so among my acquaint- 

 ance; There are also many little helps of simple contrivances 

 to further the first acquirement ot this plain branch of the art ; 

 that, if you approve the idea, I shall with pleasure transfer from 

 my portfolio : but with respect to the application of this already 

 described, it will be necessary to permi«;e, that the scale should 

 be longer than the drawing-book each way ; by which means, 

 by barely sliding it to the right or left, you can at pleasure 

 place your point of sight ?nore or less to the right, or left, or 

 middle of the horizon ; and, to be prepared for all circum- 

 stances, it would be as well to he provided also with a scale 

 having a high horizon, and another vvitl) a very low one, such 

 as the Dutch painters generally used, and which ever produces 

 a picturesque effect, by giving many profiles of the elevations, 



and multiplyin'2i; the lines of light.:. '^'^1^ ^^^Y ^^- 



T-L I y- L c n . -L ^ ,- pedient and 



I bus you have an easy expedient tor a nrst help — practice practice will 



will accomplish thej-est; for we all know, or should know, ^""^plete the 



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