The rear sled is sometimes arranged to swivel like the front sled and to be steered by a second steersman, somewhat after the fashion of a long hook-and-ladder truck. This gives good command of the double-runner on curves.
Gymnastic Apparatus.—It will, in most cases, be out of the question for you to attempt to put up any building roomy enough for a "gym," but sometimes a number of you can club together and get the use of some vacant room in which satisfactory apparatus can be fitted at moderate expense. Some of it may be rather primitive compared with the mechanism of a modern college gymnasium, but will answer the purpose so far as getting up muscle is concerned. Most of you can find a place for one or more pieces of apparatus, either indoors or out. Much outdoor apparatus can be supported on posts driven into the ground, or even by fastening to trees. The outdoor apparatus is usually easier and cheaper to make, but has the obvious disadvantages of not being usable in bad weather or winter, to any great extent, and will not last so long on account of exposure to the weather. If, however, you fix things the right way and take the movable parts indoors during the bad weather, such a "gym" will last until it is outgrown, or until the next generation grows up to build a new one. If indoors have the room well ventilated. Often the second story of a barn makes a capital gymnasium. The few simple pieces of apparatus given here will be treated independently, as it is of course impossible to tell how you will be obliged to arrange them. You can vary the designs or proportions to suit the circumstances.
White ash, hickory, oak, hard pine, and for some purposes fir, spruce, and white pine, are suitable for gymnastic apparatus. For everything which is to stand violent strain or wrenching, as the horizontal bars, vaulting poles, and such things, use air-dried stock, if possible, avoiding kiln-dried, as the latter is more brittle and inelastic, and often utterly unfit for such uses (see Chapter III.). Of course for such parts only the toughest woods should be used, as white ash, hickory, oak, spruce.
Parallel Bars.—A useful form (and not beyond the skill of an amateur) is shown in Fig. 261. The height must, of course, depend upon the gymnast, and can range from 3' 6" to 5' 6", the width inside (between the bars) from 14" to 19", and the length from 6' to 8'.
Fig. 261.
Before beginning work read carefully Marking, Rule, Square, Saw, Plane, in [Part V]., and look up any other references.
The base of the apparatus can be simply made of 2" × 6" planks, as shown in Fig. 261, and fastened by screws (see Screws), or, as shown in Fig. 262, the pieces can be halved at their intersections (see Halving), in which case thicker stock may be used. For a small pair of bars the planks for the base can be somewhat lighter.