Fig. 238.
A bow-gun or crossbow (Fig. 237) can be made on the same principle, using a bow instead of the elastic, and inserting it in a hole made through an enlargement of the under side of the barrel (Fig. 238).
Sleds.—Common sleds can be bought so cheaply that it is hardly worth while, as a rule, to make them. Many are so poorly made, however, and will stand so little rough usage, that a few suggestions may be of value if you should wish to make a really serviceable one yourself.
Take the dimensions from any sled which suits you. Avoid making your sled too high, however, as one ten or twelve inches high will coast no better than a low sled, and requires much more bracing to be strong.
Before beginning work read carefully Marking, Rule, Square, Saw, in [Part V]., and look up any other references.
Fig. 239.
The runners and cross-pieces should be of straight-grained oak, maple, ash, or other strong wood; 7/8" stock will do. Mark the runners carefully on the wood, according to your working-drawing (Fig. 239), and before sawing them out bore the holes for the rope (see Boring). Saw out the runners, or have them sawed by machine, and see that the curves are the same on each.