Fig. 565.
In scribing with the chisel, the edge is drawn along with one corner slightly raised and the flat side next the straight-edge, holding the tool either like a pencil or for deeper scoring as in Fig. 565.
In all marking and scribing, whether with pencil, awl, knife, chisel, or other tool, be sure that the marking edge is kept close up to the rule, straight-edge, or square, as it will often tend to follow the grain of the wood and run off the line, and will sometimes force the straight-edge or square out of position if the latter is not held firmly.
Do not try to stop lines which meet at a given point, but let them cross one another when they will not show in the finished work, as it is quicker to do so and the crossing of two lines marks a point more accurately than a dot. For work to be finished, however, scoring the surface with lines should be avoided wherever they will show, as they will become conspicuous after the work is finished.
THIN RULE—FINE WORK.
Fig. 566.
THICK RULE—ROUGH WORK.
Fig. 567.
In marking lines with a straight-edge or ruler you must be careful that it does not slip. If it is long you can put weights on it. To mark a line accurately through given points, the ruler should not quite touch the points, but be pushed almost up to them and equally distant from each (Fig. 566). This will give you a clear view of both points so that you can be sure that the pencil or whatever you mark with will go as nearly as possible through the centre of each. Bearing the pencil against the edge of the ruler, you can slant it a trifle till the pencil-point will just coincide with the given point on the wood, and, keeping the same inclination, move the pencil along the ruler, and it should also go through the second given point. This applies to a regular ruler with a comparatively thin edge, and to fine work only. In marking by a thick edge, or where extreme nicety is not required, you will of course put the straight-edge right up to the points and run the pencil-point along in the angle (Fig. 567).
Besides marking lines, the straight-edge (in some form), is used to determine whether a surface is true. See Straight-edge.