- 13. Position. The draughtsman should sit upright and not bend over his drawing, as that cramps the work and leads him to look, while working, at only a small portion of his drawing instead of comprehending the whole at a glance.
The surface to receive the drawing must be held at right angles to the direction in which it is seen, otherwise the drawing will be distorted. by the foreshortening of the surface. A rectan gular surface such as a sheet of paper is at right angles to the direction in which it is seen when all four corners are equally. distant from the eye. A fairly accurate test may be made in the following manner: Locate the center of the paper by drawing the diagonals. Flat against this point place the unsharpened end of a pencil. Tip the surface until the length of the pencil disappears and only the point and sharpened end are visible, then the surface will be at right angles to a line drawn from the eye to its center. The pencil represents this line for a part of the distance because if properly held it is it right angles to the surface.
Before trying to draw any definite forms the student should practice diligently drawing straight lines in horizontal, vertical, and oblique positions, and also circles and ellipses.
pencil. Try also making the exercises with different widths of line regulated by the bluntness of the point, and do at least one set using the solid ink pencil and making very wide lines as near together as is possible without fusing one line with another. In all of these exercises the lines should each be drawn with one pen cil stroke without lifting the pencil from the paper and absolutely no corrections of the line should be made.
In drawing these larger circles the free arm movement will be found necessary and the lines may be swept about a number of times for the purpose of correcting the first outline and giving practice in the arm movement. As the circles increase in diameter the difficulty of drawing them with accuracy by a single stroke increases also, but instead of erasing the faulty positions and laboriously patching the line, it is better to make the correc tions as directed, by sweeping other lines about until a mass of lines is formed which gives the shape correctly: The single outline desired will be found somewhere within the mass of lines and may be accented with a darker line and the other trial lines erased.
Draw a series of ten ellipses, Fig. 3, with a long diameter of half an inch, forming each with a single pencil stroke. Follow with a group of ten, having the long.diameter one inch in length, joining each outline with a single pencil stroke. Proceed with a set having a long diameter of two inches and a set with a long diameter of three inches. Follow the same instructions for these last two groups as were laid down for drawing the larger circles, that is sweep the lines about several times with the free arm movement.