The criterion of a good set of drawings is that with a properly prepared specification they are complete in themselves and require no explanation.
A “break” in a figure or object in a drawing is shown in rough irregular lines, as in [fig. 134], on [page 131]; this is useful when the paper is not large enough to show the whole.
Never use a sloping line in writing fractions on a drawing. The objection arises from the fact that such a dimension as 13⁄16, if written with the inclined line, unless very distinctly executed, may be read as 13⁄16.
In inking do not draw the lines further than you wish them to go, but in penciling it is well to extend the lines, free up.
Never use a scale for a ruler.
Do not overload the pen with ink.
Having filled the pen, nearly close the nibs and try the width of the line on a piece of paper or the margin of the drawing.
Never refill or lay the pen aside without first cleaning it.
The application of the science of geometry to the drawing-board is absolutely necessary to success, for the reason that the whole fabric of mechanical drawing rests on the principles of geometry, which is well termed the science of measurements.
Section lines should be the last inked and always without previous penciling.