Wood: Maple, or any close-grained hard wood.

Preparatory: Same as in Fig. 1.

Exercises.

1, 2. Same as in Fig. 1.

3, 4. Same as in Fig. 5, except that in planing the edges, especial care must be used that they are perfectly straight. It is better to be guided entirely by the eye in this, but if necessary, a steel straight-edge may be used for the final test. In work requiring such a degree of accuracy as this, the tools should be in perfect order, and so adjusted that they will take the thinnest possible shaving.

Fig ll.

5.   In making the graduations, do not allow the students to lay out one inch at a time. Instead, lay out all the inch graduations at once, then the half inch, then the quarter inch, and eighths if desired. Insist upon absolute accuracy.

6.   If the wood is straight grained, the rule may be planed upon both sides. If this cannot be done well, the students may sandpaper the sides to a smooth surface. If care is used in selecting the wood for this model, this may be done satisfactorily.

7.   Finish with two coats of shellac, rubbed down in oil. See Fig. 6, Ex. 5.

8.   If a set of 3/16" sharp steel figures is available, the inches may be marked before the rule is shellacked; otherwise the figures should be made

with black drawing ink after the model has been rubbed with oil and polished.