SONS I.\ 



137 



fitlnnv 

 : ) ; UIM 



. 

 find tl::it iln- line 'i ' i- lirtiwn from I r 1 t>. the 



Kirullfl to our of tli.- retiring lines i.f i pl;m, 



;rli give* V p 1 ; also a e I to / c, tho 



other retiring lino of tho ground plan which gives UH \ r _'. 

 But if tho station point had boon further off, a* at s v '2, tlio 

 line a b would IIUM- l".n from s r 2 to h ; therefore at h 

 would thru ho found v i- 1 ; so on tho other sido tho v r ~1 

 would h:a l>. .11 at i. Suppose the station point woro placed at 

 8 P 3, then tho vauisliing points would bo nearer each other. 

 So it will bo 8e;n, thu further tho vanishing joints arc apart, 

 the further we arc from tho object ; and tin- IKMHT \vo aro to tho 

 object tho nearer together aro tho vanishing points. Our object, 



. Iraco out the lino* a * and I f in 

 . i- -J ; a.u-1 tli': i.:.' - OH iuj other 

 i I d, will meet ut v i- 1. In an engraving, tho 

 vanishing points for all hori/.outul retiring line* may be found 

 in thin wuy, and tlx-y will dut<-rmino al*o tho lino of night which 

 runs thr..u/h UICKO poii.! ,. If ho discover that the** horizontal 

 retiring lin.-i do not meet in tho aame point, it will be becauoo 

 not parall" 1 retiring lines; that is, the object* them* 

 elves aro not placed in a parallel position with each other. This 

 leada to another observation connected with this last remark ; if 

 thcro are fifty retiring linos, and all parallel, there will be only 

 ono vanishing point for them all; but if amongst theM fifty 

 there aro not two parallel, thcro will bo fifty vanishing point*. 

 As tho pupil, wo hopo, will clearly comprehend this interesting 

 feature in perspective drawing, ho may apply the rule when he 

 has an engraving before him. Wo know that the rectangular 

 topa and bottoms of windows and doors are horizontal, and 



V.P?. 



\ \ 



then, in giving this littlo explanation, is to account for placing 

 the vanishing points. To carry this rule out by producing a 

 drawing of the elevation of the house from the ground plan, will 

 be considered hereafter. 



By this explanation wo only undertake to satisfy our pupils 

 that we can make a correct drawing of tho building if the 

 vanishing point was at h, b, or A- ; only observe, tliat if wo 

 approached too near, tho angle of sight, in, would be too large, 

 so much so as probably to become as great, or greater than GO . 

 (See p. 72.) While writing these remarks on Angular Per- 

 spective, we found that it was absolutely necessary to give theso 

 geometrical reasons for tho positions of tho vanishing points, 

 because as many lines in a picture retire and vanish elsewhere 

 than at the point of sight, we felt bound to givo thcso reasons, 

 whi'.-h noed not cause tho pupil to imagine there is anytliing to 

 discourage him, as tho mode of finding them in a picture, as well 

 as when drawing from Nature, is very simple. Here, then, tho 

 pupil may ask, ' If I have a drawing before me to copy, in which 

 the vanishing points are not marked, how shall I find them ? " 

 Let us suppose the copy is an engraving (and the vanishing 

 points are never shown in engravings), let him trace out tho 

 retiring lines in the picture wo think there can be no difficulty 

 ia recognising them theso lines traced out will give the vanishing 



parallel with tho eaves and horizontal ridges of roofs, the courses 

 of the bricks, etc. Let him trace out as many of theso lines 

 as he can, if he understands they are intended, as in the object 

 itself, to go off in tho same direction, and he will find them meet 

 at tho same vanishing point, and soon discover whether tho 

 engraving is correct or not in tho grammar. The uneducated eye 

 may not detect small faults in tho general appearance of the 

 engraving, and thousands of drawings and paintings by really 

 clever artists pass muster, and aro admired, although they may 

 bo full of mistakes ; just as in speaking, tho grammatical errors 

 habitually made by uneducated men are not even known to be 

 such among themselves, but an educated man will notice them, 

 although ho may not remark upon them. After the pupil has 

 discovered the vanishing point for the horizontal retiring lines 

 in the engraving, ho will then have found tho position of tho 

 line of sight j then, in making his drawing, ho must begin by 

 placing this v P on his paper, and proceed by marking in 

 the nearest lino to tho vanishing point, and so on, line after 

 line, as we have before said. We know from experience tho 

 great advantage of this method, and have frequently remarked 

 the rapid progress that has been mado by those who havo feared 

 that drawing was an art too difficult for them to attain. 



Tho method of drawing Fig. 38 will be as follows : Draw the 



