ON THE CAMERA HJCIDA. S75 



of the paper on which, and the pencil by which it is to be The proce* 



Imitated : of course the draughtsman will copy correctly on s ^Jj t *J' <te " 



the lower part those objects which he sees in the upper part 



of the glass ; bat these objects constitute but a small part 



of the whole view; if the remainder is to be attained it 



must be with great trouble and difficulty : it is true that by 



moving my head to one side, and looking diagonally acros* 



the eye glass, I could see objects that were not risible 



upon looking directly into it, and thus by moving my head 



from one side to the other I could get all the horizontal 



lines, and those lines which approach to the horizontal 



position upon the paper, so that by this method I could 



get all the horizontal lines that were within the range of the 



instrument or the drawing: but it was impossible, by any 



artifice to do as much with the perpendicular lines, or 



those which approach to the perpendicular direction, with- 



out altering the position of the glass, and in doing this it 



was found impossible to connect the different portions of 



the *cene that were viewed upon changing the position of 



the glass, with a degree of truth comparable to what may 



"be attained by the camera obscura without any trouble 



at all. 



The reader will perhaps comprehend the difficulty if he 

 imagines the great tree in the foreground to be divided 

 horizontally into four or more parts, each of which must 

 be seen by itself and drawn by itself: the glass must then 

 be shifted so as to see and draw another portion without 

 seeing that which had first been drawn, and so on till the 

 whole was completed. Independent of the trouble and 

 waste of time that would be necessary to shift the glass, 

 if it could be done with accuracy, the circumstance of 

 not being able to see the whole of the scene while one 

 is drawing it, and of course comparing the effect of the 

 whole is extremely unpleasant: the instrument must be 

 removed from the paper before the effect of the drawing 

 could be seen, and if it should be necessary to correct it, 

 it is next to impossible to replace it with sufficient accuracy 

 to avoid making false lines, and of course destroying the 

 truth of the representation. 



I have stated the in conveniences that /have found, in Method of 



making ***** 



