Mechanical Drawing Self-Taught / Comprising instructions in the selection and preparation of drawing instruments, elementary instruction in practical mechanical drawing; together with examples in simple geometry and elementary mechanism, including screw threads, gear wheels, mechanical motions, engines and boilers

by Joshua Rose

Fig. 11.

Fig 12.

For simple cleaning purposes, or to efface the pencil lines when they are drawn very lightly, squares of sponge-rubber answer admirably, these being furnished by the dealers in drawing materials.

A piece of bread will answer a similar purpose, but it is less convenient.

For glazed surface paper, as Bristol-board, the smoothest rubber must be used, the grade termed velvet rubber answering well.

THE DRAWING PAPER.

Whatever kind of drawing paper be used it should be kept dry, or the ink, however good it may be, will be apt to run and make a thick line that will not have the sharp, clean edges necessary to make lines look well.

Drawing paper is made in various qualities, kinds, and forms, as follows: The sizes and names of paper made in sheets are: