The Boy Mechanic Part 95

[Ill.u.s.tration: Lantern]

Remove the bottom of the box, and nail it in position as shown at A. Remove one end, and replace as shown at B. Drive a short wire nail through the center of the opposite end to serve as a seat for the candle, C. The lamp is finished by tacking two or more layers of yellow post-office paper over the aperture D, bringing the paper well around to the sides and bottom of the box to prevent light leakage from the cracks around the edges, says Photo Era.

The hinged cover E, is used as a door, making lighting and tr.i.m.m.i.n.g convenient. The door may be fastened with a nail or piece of wire. It is well to reinforce the hinge by gluing on a strip of cloth if the lamp is to be in use more than once or twice. This lamp is safe, for the projecting edges of A and B form light-s.h.i.+elds for the ventilation orifice and the crack at the top of the hinged cover, respectively. Moreover, since the flame of the candle is above A, only reflected and transmitted light reaches the plate, while the danger of igniting the paper is reduced to a minimum.

** Runny Paint [340]

The paint will sag and run if too much oil is put in white lead.

** Camps and How to Build Them [341]

There are several ways of building a temporary camp from material that is always to be found in the woods, and whether these improvised shelters are intended to last until a permanent camp is built, or only as a camp on a short excursion, a great deal of fun can be had in their construction. The Indian camp is the easiest to make. An evergreen tree with branches growing well down toward the ground furnishes all the material. By chopping the trunk almost through, so that when the tree falls the upper part will still remain attached to the stump, a serviceable shelter can be quickly provided. The cut should be about 5 ft. from the ground.

Then the boughs and branches on the under side of the fallen top are chopped away and piled on top. There is room for several persons under this sort of shelter, which offers fairly good protection against any but the most drenching rains.

The Indian wigwam sheds rain better, and where there are no suitable trees that can be cut, it is the easiest camp to make.

Three long poles with the tops tied together and the lower ends s.p.a.ced 8 or 10 ft. apart, make the frame of the wigwam. Branches and brush can easily be piled up, and woven in and out on these poles so as to shed a very heavy rain.

The brush camp is shaped like an ordinary "A" tent. The ridge pole should be about 8 ft. long and supported by crotched uprights about 6 ft. from the ground. Often the ridge pole can be laid from one small tree to another. Avoid tall trees on account of lightning. Eight or ten long poles are then laid slanting against the ridge pole on each side. Cedar or hemlock boughs make the best thatch for the brush camp. They should be piled up to a thickness of a foot or more over the slanting poles and woven in and out to keep them from slipping. Then a number of poles should be laid over them to prevent them from blowing away. In woods where there is plenty of bark available in large slabs, the bark lean-to is a quickly constructed and serviceable camp. The ridge pole is set up like that of the brush camp. Three or four other poles are laid slanting to the ground on one side only. The ends of these poles should be pushed into the earth and fastened with crotched sticks.

Long poles are then laid crossways of these slanting poles, and the whole can be covered with brush as in the case of the brush camp or with strips of bark laid overlapping each other like s.h.i.+ngles. Where bark is used, nails are necessary to hold it in place. Bark may also be used for a wigwam and it can be held in place by a cord wrapped tightly around the whole structure, running spiral-wise from the ground to the peak. In the early summer, the bark can easily be removed from most trees by making two circular cuts around the trunk and joining them with another vertical cut. The bark is easily pried off with an ax, and if laid on the ground under heavy stones, will dry flat. Sheets of bark, 6 ft. long and 2 or 3 ft. wide, are a convenient size for camp construction.

The small boughs and twigs of hemlock, spruce, and cedar, piled 2 or 3 ft. deep and covered with blankets, make the best kind of a camp bed. For a permanent camp, a bunk can be made by laying small poles close together across two larger poles on a rude framework easily constructed. Evergreen twigs or dried leaves are piled on this, and a blanket or a piece of canvas stretched across and fastened down to the poles at the sides. A bed like this is soft and springy and will last through an ordinary camping season without renewal. A portable cot that does not take up much room in the camp outfit is made of a piece of heavy canvas 40 in. wide and 6 ft. long. Four-inch hems are sewed in each side of the canvas, and when the camp is pitched, a 2-in. pole is run through each hem and the ends of the pole supported on crotched sticks.

[Ill.u.s.tration: Camp Details]

Fresh water close at hand and shade for the middle of the day are two points that should always be looked for in. selecting a site for a camp. If the camp is to be occupied for any length of time, useful implements for many purposes can be made out of such material as the woods afford. The simplest way to build a crane for hanging kettles over the campfire is to drive two posts into the ground, each of them a foot or more from one end of the fire s.p.a.ce, and split the tops with an ax, so that a pole laid from one to the other across the fire will be securely held in the split.

Tongs are very useful in camp. A piece of elm or hickory, 3 ft.

long and 1-1/2 in. thick, makes a good pair of tongs. For a foot in the middle of the stick, cut half of the thickness away and hold this part over the fire until it can be bent easily to bring the two ends together, then fasten a crosspiece to hold the ends close together, shape the ends so that anything that drops into the fire can be seized by them, and a serviceable pair of tongs is the result. Any sort of a stick that is easily handled will serve as a poker. Hemlock twigs tied around one end of a stick make an excellent broom. Movable seats for a permanent camp are easily made by splitting a log, boring holes in the rounded side of the slab and driving pegs into them to serve as legs. A short slab or plank can easily be made into a three-legged stool in the same way.

Campers usually have boxes in which their provisions have been carried. Such a packing box is easily made into a cupboard, and it is not difficult to improvise shelves, hinges, or even a rough lock for the camp larder.

A good way to make a camp table is to set four posts into the ground and nail crosspieces to support slabs cut from chopped wood logs to form a top. Pieces can be nailed onto the legs of the table to hold other slabs to serve as seats, and affording accommodation for several persons.

** Brooder for Small Chicks [343]

A very simple brooder can be constructed by cutting a sugar barrel in half and using one part in the manner

[Ill.u.s.tration: Brooder for Young Chicks Kept Warm with a Jug of Boiling Water]

described. Line the inside of the half barrel with paper and then cover this with old flannel cloth. Make a cover for the top and line it in the same manner. At the bottom cut a hole in the edge, about 4 in. deep and 4 in. wide, and provide a cover or door. The inside is kept warm by filling a jug with boiling water and setting it within, changing the water both morning and night. When the temperature outside is 10 deg. the interior can, be kept at 90 or 100 deg., but the jug must be refilled with boiling water at least twice a day.

** Faucet Used as an Emergency Plug [343]

A bra.s.s faucet split as shown at A during a cold spell, and as no suitable plug to screw into the elbow after removing the faucet was at hand, I drove a small cork, B, into the end of the faucet and screwed it back in place. The cork converted the faucet into an

[Ill.u.s.tration: A Tight-Fitting Cork Driven into a Cracked Faucet Converted It into an Emergency Plug]

emergency plug which prevented leakage until the proper fitting to take its place could be secured.

--Contributed by James M. Kane, Doylestown, Pa.

** Automatic Electric Heat Regulator [344]

It is composed of a closed gla.s.s tube, A, Fig. 1, connected by means of a very small lead pipe, B, to another

[Ill.u.s.tration: Heat Regulator]

gla.s.s tube, C, open at the bottom and having five pieces of platinum wire (1, 2, 3, 4 and 5), which project inside and outside of the tube, fused into one side. This tube is plunged into an ebonite vessel of somewhat larger diameter, which is fastened to the base by a copper screw, E. The tube C is filled to a certain height with mercury and then petroleum. The outer ends of the five platinum wires are soldered to ordinary copper wires and connections made to various points on a rheostat as shown. The diagram, Fig. 2, shows how the connections to the supply current are made. The apparatus operates as follows: The tube is immersed in the matter to be heated, a liquid, for instance. As

[Ill.u.s.tration: Wiring Diagram Showing How the Connections to a Source of Current Supply are Made]

the temperature of this rises, the air expands and exerts pressure on the petroleum in the tube C so that the level of the mercury is lowered. The current is thus compelled, as the platinum wires with the fall of the mercury are brought out of circuit, to pa.s.s through an increasing resistance, until, if necessary, the flow is entirely stopped when the mercury falls below the wire 5.

With this very simple apparatus the temperature can be kept constant within a 10-deg. limit, and it can be made much more sensitive by increasing the number of platinum wires and placing them closer together, and by filling the tube A with some very volatile substance, such as ether, for instance. The petroleum above the mercury prevents sparking between the platinum wire and the mercury when the latter falls below anyone of them.

** Repairing a Washer on a Flush Valve [344]

When the rubber washer on the copper flush valve of a soil-basin tank becomes loose it can be set by pouring a small quant.i.ty of paraffin between the rubber and the copper while the valve is inverted, care being taken to have the rubber ring centered. This makes

[Ill.u.s.tration: Flush Valve]

a repair that will not allow a drop ot water to leak out of the tank.

--Contributed by Frank Jermin, Alpena, Michigan.

** Cleaning Discolored Silver [344]

A very quick way to clean silver when it is not tarnished, but merely discolored, is to wash the articles in a weak solution of ammonia water. This removes the black stains caused by sulphur in the air. After cleaning them with the solution, they should be washed and polished in magnesia powder or with a cloth. This method works well on silver spoons tarnished by eggs and can be used every day while other methods require much time and, therefore, cannot be used so often.

** How to Make a Small Electric Motor [345]

By W. A. ROBERTSON

The field frame of the motor, Fig. 1, is composed of wrought sheet iron, which may be of any thickness so that, when several pieces are placed together, they will make a frame 3/4 in. thick. It is necessary to layout a template of the frame as shown, making it 1/16 in. larger than the dimensions given, to allow for filing to shape after the parts are fastened together. After the template is marked out, drill the four rivet holes, clamp the template, or pattern, to the sheet iron and mark carefully with a scriber. The bore can be marked with a pair of dividers, set at 1/8 in. This will mark a line for the center of the holes to be drilled with a 1/4-in. drill for removing the unnecessary metal. The points formed by drilling the holes can be filed to the pattern size. Be sure to mark and cut out a sufficient number of plates to make a frame 3/4 in. thick, or even 1/16 in. thicker, to allow for finis.h.i.+ng.

After the plates are cut out and the rivet holes drilled, a.s.semble and rivet them solidly, then bore it out to a diameter of 2-3/4 in. on a lathe. If the thickness is sufficient, a slight finis.h.i.+ng cut can be taken on the face. Before removing the field from the lathe, mark off a s.p.a.ce, 3-3/8 in. in diameter, for the field core with a sharp-pointed tool, and for the outside of the frame, 4-1/2 in. in diameter, by turning the lathe with the hand. Then the field can be finished to these marks, which will make it uniform in size. When the frame is finished so far, two holes, 3-3/8 in.

between centers, are drilled and tapped with a 3/8-in. tap. These holes are for the bearing studs. Two holes are also drilled and tapped for 1/4-in. screws, which fasten the holding-down lugs or feet to the frame. These lugs are made of a piece of 1/8-in. bra.s.s or iron, bent at right angles as shown.