The new international encyclopaedia . Fig. the more important points and lines, PVR is the principal visual ray. actual or assumed, the horizontal line must below. The horizontal line in nearly all cases to be le\el with the spectators eye.(.5) Tlie vertical line, which is drawn from thesupposed position of the sketcher, perpendicularto the ground and horizontal lines, meeting thelatter in a point which is called the point ofsight, or centre of the |)icture. The vertical linehas no representative in nature, and is merely amechanical adjunct to the construct
The new international encyclopaedia . Fig. the more important points and lines, PVR is the principal visual ray. actual or assumed, the horizontal line must below. The horizontal line in nearly all cases to be le\el with the spectators eye.(.5) Tlie vertical line, which is drawn from thesupposed position of the sketcher, perpendicularto the ground and horizontal lines, meeting thelatter in a point which is called the point ofsight, or centre of the |)icture. The vertical linehas no representative in nature, and is merely amechanical adjunct to the construction of thepicture, all vertical lines in nature being parallelto it in the picture. The point of sight, being thepoint directly op])osile to the observer, is oftenplaced in the centre of the picture; but we very A / /o. p p- Fig. 2. The lines 00 converge to the accidental point aerial, and PP to the accidentalpoint terrestrial. fre<(ucntly find it on the right or left side,thougli always, of course, on the horizontal lines which in nature are perpendicular tothe ground line, or to a vertical plane which israised upon it as a base, meet in the point ofsight, which is thus their vanisMng point (seethe line of the tops and bottoms of the pillars inFig. 1). The pointa of distance are two pointsin the horizontal line on each side of the pointof sight, and in a direct sketch are at a distance (in nature )at an aii^le of 4o to tlic liase line:but. in all cases, the two points of distance areabout twice as far apart as the eye is from thepicture. One important use of the points of dis-tance is to define the distance of objects in a row( Fig. 1) from each other. For this purpose, twopoints of distance arc not necessary, as, when theposition of one pillar is found, that of the op-posite is at once
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Keywords: ., bo, bookcentury1900, bookdecade1900, bookpublishernewyorkdoddmead
