Perspective and geometrical drawing adapted to the use of candidates for second and third-class teachers' certificates . bjects appear to diminish in size as they recede from theeye, and vice versa. At the centre of vision all objects have no apparent magni-tude, and must be represented by a point, and steadily in-creased in size till they approach the eye. This is why railson a straight piece of railway appear to meet in the distance,though everywhere the distance between them is the same. Now, if we stood on a straight piece of track, and if othertracks were laid on each side and parallel wi
Perspective and geometrical drawing adapted to the use of candidates for second and third-class teachers' certificates . bjects appear to diminish in size as they recede from theeye, and vice versa. At the centre of vision all objects have no apparent magni-tude, and must be represented by a point, and steadily in-creased in size till they approach the eye. This is why railson a straight piece of railway appear to meet in the distance,though everywhere the distance between them is the same. Now, if we stood on a straight piece of track, and if othertracks were laid on each side and parallel with it, every traclwould appear to vanish at the same point directly in front ofus, hence the rule : Lines parallel to the line of direction will vanish at thecentre of vision. (Fig. 3.) Thus, let C be centre of vision, and AA, BB the ends ofparallel lines : they will all meet at C, and all the lines drawnfrom C to AB will really be right angles, however differentthey may appear to be. Now draw DD parallel to AA, and INTRODUCTION. 13 since the distance from A to A is always the same as from Dto D, we have the rule :. Parallel lines drawn between vanishing lines are of equallength, and, conversely, the lines joining the extremities ofequal parallel lines will vanish to a point.
Size: 1270px × 1967px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectgeometricald, booksubjectperspective
