Part 14 (1/2)

To wire the apparatus, refer to the sketch and you will see that jar No. 1 is connected to point No. 1 on switch; No. 2, on No. 2, and so on until all is complete and we have one remaining point on switch. Above the jars place a wire to suspend the other or top disks in the solution. This wire is also connected to one terminal on the motor and to remaining point on switch. The arm of the switch is connected to one terminal of battery, or source of current, and the other terminal connected direct to remaining terminal of motor.

Put arm of switch on point No. 1 and lower one of the top disks in jar No. 1 and make contact with wire above jars. The current then will flow through the motor. The speed for each point can be determined by lowering top disks in jars. The top disk in jar No.

2 is lower down than in No. 1 and so on for No. 3 and No. 4. The connection between point No. 5 on switch, direct to wire across jars, gives full current and full speed.

** How to Build a Toboggan Sled [44]

By A. BOETTE

The first object of the builder of a sled should be to have a ”winner” both in speed and appearance. The accompanying instructions for building a sled are designed to produce these results.

The sled completed should be 15 ft. 2 in. long by 22 in. wide, with the cus.h.i.+on about 15 in. above the ground. For the baseboard select a pine board 15 ft. long, 11 in. wide and 2 in. thick, and plane it on all edges. Fit up the baseboard with ten oak foot-rests 22 in. long, 3 in. wide and 3/4 in. thick. Fasten them on the under side of the baseboard at right angles to its length and 16 in. apart, beginning at the rear. At the front 24 or 26 in.

will be left without cross bars for fitting on the auto front. On the upper side of the cross bars at their ends on each side screw a piece of oak 1 in. square by 14 ft. long. On the upper side of the baseboard at its edge on each side screw an oak strip 3 in.

wide by 3/4 in. thick and the length of the sled from the back to the auto front. These are to keep the cus.h.i.+on from falling out.

See Fig. 1. For the back of the sled use the upper part of a child's high chair, taking out the spindles and resetting them in the rear end of the baseboard. Cover up the outside of the spindles with a piece of galvanized iron.

The construction of the runners is shown by Figs. 2 and 3. The stock required for them is oak, two pieces 30 in. by 5 in. by 1-1/4 in., two pieces 34 in. by 5 in. by 1-1/4 in., two pieces 14 in. by 6 in. by 2 in., and four pieces 14 in. by 2 in. by 1 in.

They should be put together with large screws about 3 in. long.

Use no nails, as they are not substantial enough. In proportioning them the points A, B and C, Fig. 2, are important. For the front runners these measurements are: A, 30 in.; B, 4 in.; C, 15-1/2 in., and for the rear runners: A, 34 in.; B, 7 in. ; C, 16-1/2 in.

The screw eyes indicated must be placed in a straight line and the holes for them carefully centered. A variation of 1/16 in. one way or another would cause a great deal of trouble. For the steel runners use 3/8 in. cold-rolled steel flattened at the ends for screw holes. Use no screws on the running surface, however, as they ”s.n.a.t.c.h” the ice.

The mechanism of the front steering gear is shown at Fig. 3. A 3/4-in. steel rod makes a good steering rod. Flatten the steering rod at one end and sink it into the wood. Hold it in place by means of an iron plate drilled to receive the rod and screwed to block X. An iron washer, Z, is used to reduce friction; bevel block K to give a rocker motion. Equip block X with screw eyes, making them clear those in the front runner, and bolt through. For the rear runner put a block with screw eyes on the baseboard and run a bolt through.

Construct the auto front (Fig. 4) of 3/4-in. oak boards. The ill.u.s.tration shows how to shape it. Bevel it toward all sides and keep the edges sharp, as sharp edges are best suited for the bra.s.s tr.i.m.m.i.n.gs which are to be added. When the auto front is in place enamel the sled either a dark maroon or a creamy white. First sandpaper all the wood, then apply a coat of thin enamel. Let stand for three days and apply another coat. Three coats of enamel and one of thin varnish will make a fine-looking sled. For the bra.s.s tr.i.m.m.i.n.gs use No. 27 B. & S. sheet bra.s.s 1 in. wide on all the front edges and pieces 3 in. square on the cross bars to rest the feet against. On the door of the auto front put the monogram of the owner or owners of the sled, cutting it out of sheet bra.s.s.

For the steering-wheel procure an old freight-car ”brake” wheel, bra.s.s plated. Fasten a horn, such as used on automobiles, to the wheel.

Make the cus.h.i.+on of leather and stuff it with hair. The best way is to get some strong, cheap material, such as burlap, sew up one end and make in

[Ill.u.s.tration: Construction a ”Winner” Toboggan Sled]

the form of an oblong bag. Stuff this as tightly as possible with hair. Then get some upholstery b.u.t.tons, fasten a cord through the loop, bring the cord through to the underside of the cus.h.i.+on, and fasten the b.u.t.ton by slipping a nail through the knot. Then put a leather covering over the burlap, sewing it to the burlap on the under side. Make the cus.h.i.+on for the back in the same way. On top of the cus.h.i.+on supports run a bra.s.s tube to serve the double purpose of holding the cus.h.i.+on down and affording something to hold on to.

If desired, bicycle lamps may be fastened to the front end, to improve the appearance, and it is well to have a light of some kind at the back to avoid the danger of rear-end collisions.

The door of the auto front should be hinged and provided with a lock so that skates, parcels, overshoes, lunch, etc. may be stowed within. A silk pennant with a monogram adds to the appearance.

If desired, a brake may be added to the sled. This can be a wrought-iron lever 1-1/2 in. by 1/2 in. by 30 in. long, so pivoted that moving the handle will cause the end to sc.r.a.pe the ice. This sled can be made without lamps and horn at a cost of about $15, or with these for $25, and the pleasure derived from it well repays the builder. If the expense is greater than one can afford, a number of boys may share in the owners.h.i.+p.

** Burning Inscriptions on Trees

Sc.r.a.pe off the bark just enough to come to the first light under coating, which is somewhat moist. With a lead pencil make an outline of the inscription to be burnt on the tree and bring, the rays of a large magnifying gla.s.s not quite to a fine focus on the same. The tree will be burnt along the pencil marks, and if the gla.s.s is not held in one spot too long, the inscription will be burnt in as evenly as if it had been written.

--Contributed by Stewart H. Leland, Lexington, Ill.