A few years ago the boys of New England invented a new kind of sled and called it a single-runner coaster or jumper-coaster. They sit upon it, keeping their balance with the feet, and it is remarkable how rapidly and easily they go downhill on this queer-looking affair, and without the slightest danger of toppling over. Fig. 6.
The coaster is very simple in construction and any boy can make it from pine or hard-wood, the latter being preferable as it has more body and is heavier. The runner is forty-two inches long, one inch and a half thick, and four inches high, curved at one end and cut at an angle at the other. The upright is of wood the same thickness and width, and eleven or twelve inches high, so that with the top board or seat and the height of the runner the coaster is sixteen or seventeen inches high; and for taller boys it can be made still higher. The seat is ten inches long and seven inches wide, and attached to the upright with screws, as shown at Fig. 7. The upright is cut from wood about ten inches wide, so that, with a compass-saw, a broad foot may be shaped at the bottom which will give a better bearing on the runner than would a narrower one.
From wood two inches wide, make two side-plates or braces to run from under the seat down half-way over the runner as shown in Fig. 7. To steady the seat at the top of the uprights cut two angle-brackets and attach them as shown in the figure drawing. A blacksmith will fashion a runner from quarter-round or thin tire iron and attach it as shown in the illustration. The runners can be held on with flat-headed screws countersunk in the iron, and after a few trips the surface of the metal will be worn bright and smooth, insuring easy and rapid running.
Every boy wants a double-runner of his own, for there seems to be nothing quite like bobbing on a sled carrying from six to ten boys—enough to give it weight and a good impetus on its downward course. A bob-sled is not at all difficult to construct, and a very satisfactory and substantial one may be made from inexpensive materials and with the tools that nearly every boy possesses. Fig. 8.
For the seat obtain a clear spruce plank ten feet long, ten inches wide, and one inch and a half thick, planed on both sides and edges. The front sled is thirty inches long and fourteen inches wide, with the sides five inches high. The rear sled is forty inches long from prow to end of runners, and is the same width and height as the front one. The sides are of hard-wood seven-eighths of an inch in thickness, and braced with cross-pieces of hard-wood two inches wide and one inch and a half thick.