抄録
To draw a perspective, we have to draw many straight lines passing through vanishing point. If vanishing point exist outside of the drawing paper, it is difficult to draw them without instrument. We devised drafter useful in such a case. This drafter consists of two main parts. One of them is like a T-square, we slide it by our left hand on a straight guide perpendicular to HL. The another part is a ruler, it is fixed to the former at a point by a pin and turns led by a oblique guide. The oblique guide is fixed to the drawing board at a point and its inclination angler, which determines the position of vanishing point, is vanable. .We draw the straight line along the ruler, all of their elongation pass through a vanishing point.
The position of vanishing point is determined at all points on HL outside of drawing paper.
