By Dan Beard
The only really necessary tools with which to work in building a jumper is an axe and an auger, but for that reason one need not throw away the contents of the tool chest. The jumper is a sleigh made from green wood, cut in the forest for the occasion; hickory saplings furnish the proper material and the denser the forest the taller and straighter the saplings will be. These are the sort of sticks you should seek for but for that reason one
The Runners
of the proposed sleigh (Fig. 463). With a good sharp axe, lop off the branches, leaving no projecting stubs; then cut two more stout sticks like the one marked with large capitals A B C D E (Fig. 464) for the top rails of the runners; after which lay the top rail on a level piece of ground and the long bottom rail alongside of it at exactly the distance from the top rail which you have decided to be the height of the proposed runner (Fig. 464).
Next cut the spokes AF, BG, CH, DJ and EK, and lay them along the runners, in the positions which you intend them to occupy in the finished frame (Fig. 464), and mark where they are to be trimmed down to fit the proposed auger holes in rail, at A B C D E, and runner at F G H J K. Also mark the places for the auger holes and scratch the direction, or angle, on the rail and runner of the slanting auger holes at the ends of the sleigh AF and EK (Fig- 464).
This done, bore the auger holes at the points marked, being careful to make the middle ones at right angles with the rail and runner, and the end ones to exactly correspond with the diagonal scratches made to guide you. Now test your spokes and see that the middle ones are of equal length and end ones of proper length to fit holes EK, AF. Trim off the spokes so that they may be forced into the holes and then drive them in place.
Take care not to make the ends of the spokes so large as to split your rail or runner or to drive them in with such force as to produce the same disastrous result; they need to be firmly fixed in place, but not forced into the auger holes with sledge hammer blows.
The Shafts
0f this jumper are the long protruding ends of the runners, and if the wood proves to be too stiff to bend properly for the correct angle of the shafts, the top of the runners may be carefully shaved off at the bending point in front of the sleigh as it is in Fig. 464. But do not do this until you have completed your jumper and tested the elasticity of the poles by lifting up the ends of the shafts, something after the manner the Yale man is doing in Fig. 465.
When one runner is finished to your satisfaction build a duplicate one as already described.
The Auger Holes
may go entirely through the top rail, but must not go through the runners, for the obvious reason that if the spokes protrude through the runners they will retard the progress of the sleigh. For ordinary purposes it is not necessary to have as many spokes to runners as are shown in Figs. 464 and 465, but the builder must here use his own judgment, as he must also do in the selection of the material. Green white ash can be split with a nail.
It requires more skill to build a light jumper than a heavy one, and the best course for a novice to pursue is to select timber heavy enough to avoid any great danger of splitting it when the spokes are driven in place.
The Frame
of the sleigh is finished when the cross braces are put in place (Fig. 465) and secured there by nails, withes, or lashings of thongs, twine or marline (Fig. 466). A glance at Fig. 465 will show the reader that, within reasonable limits, the greater the weight which rests on the runners, the less liability there is of the spokes working out of their bearings.
The Braces
may have log cabin joints to fit in similar ones cut in the top rail as shown by small diagrams marked "joints" (Fig. 465) or, if there is thought to be any danger of weakening the top rails by these joints, or if the builder is in haste, the braces can be nailed in place without having any notches at all.
(See The Gummer For Further Details)
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