A working drawing of an object consists of one or more views of that object so drawn that they make known the size, shape, kind of material, etc.
Fig. 1.
A working drawing differs from a perspective. The former represents an object as it really is, the second, represents the object as it appears. [Fig. 1].
Fig. 2.
1. Instruments.
—Special instruments are required for the making of a mechanical drawing. [Fig. 2] shows a drawing-board with paper fastened to it, also a T-square and the two triangles. A compass is needed for drawing circles and arcs of circles.
The T-square is used for drawing horizontal lines. The head must be held firmly against the edge of the board and the lines drawn from left to right. Vertical and oblique lines are drawn from the T-square upward, the triangles being held against the edge of the T-square which, at the same time, is held against the edge of the board.