Page:International Library of Technology, Volume 53.djvu/16



INSTRUMENTS AND MATERIALS.

. A drawing is a representation of objects on a plane surface by means of lines or lines and shades. When done by the use of free hand only, it is called freehand drawing or sketching; when instruments are used, so that greater exactness may be obtained, it is called Instrumental, or mechanical, drawing.

. All of the instruments and materials required for the courses In drawing are mentioned in the following descriptions:

The drawing board should be made of well-seasoned, straight-grained pine, the grain running lengthwise. For this course, the student will need a board of the following dimensions: length over all, 22½ inches; width, 16½ inches.

The drawing board illustrated in Fig. 1 is the one furnished in our students drawing outfits and can be fully recommended as possessing the qualities a good and accurate board should have. It is made of several pieces of pine wood glued together to the required width of the board. A pair of hardwood cleats is screwed to the back of the board, the screws passing through the cleats in oblong slots with iron bushings, which allow the screws to move freely when drawn by the contraction and expansion of the board. Grooves are cut through half the thickness of the board over the entire back side. These grooves take the transverse resistance out of §1 For the notice of copyright, see page immediately following the title page