All the parts should be joined together snugly and the movable parts made to slide freely and when all is complete and well sandpapered, apply two coats of shellac varnish.  Place the lamp house on the bottom board behind the condensing lens and the lantern is ready for use.

The proper light and focus may be obtained by slipping the movable parts on the board E, and when the right position is found for each, all lantern slides will produce a clear picture on the screen, if the position of the lantern and screen is not changed.  —­Contributed by Stuart Mason Kerr, St. Paul, Minn.

** A Quickly Made Lamp [329]

A very simple lamp can be made from materials which are available in practically every household in the following manner:  A cheap glass tumbler is partly filled with water and then about 1/2 in. of safe, light burning oil, placed on the water.  Cut a thin strip from an ordinary cork and make a hole in the center to carry a short piece of wick.  The wick should

[Illustration:  Lamp]

be of such a length as to dip into the oil, but not long enough.  To reach the water.  The upper surface of the cork may be protected from the flame with a small piece of tin bent over the edges and a hole punched in the center for the wick.  The weight of the tin will force the cork down into the oil.  The level of the oil should be such as to make the flame below the top of the tumbler and the light then will not be blown out with draughts.  The arrangement is quite safe as, should the glass happen to upset, the water at once extinguishes the flame.  —­Contributed by G. P. B.

** How to Make a Paper Aeroplane [329]

A very interesting and instructive toy aeroplane can be made as shown in the accompanying illustrations.  A sheet

[Illustration:  Folding the Paper]

of paper is first folded, Fig. 1, then the corners on one end are doubled over, Fig. 2, and the whole piece finished up and held together with a paper clip as in Fig. 3.  The paper clip to be used should be like the one shown in Fig. 4.  If one of these clips is not at hand, form a piece of wire in the same shape, as it will be needed for balancing purposes as well as for holding the paper together.  Grasp the aeroplane between the thumb and forefinger at the place marked A in Fig. 3, keeping the paper as level as possible and throwing it as you would a dart.  The aeroplane will make an easy and graceful flight in a room where no air will strike it.  —­Contributed by J.H.  Crawford, Schenectady, N. Y.

** Bronze Liquid [329]

Banana oil or amyl acetate is a good bronze liquid.

** A Wrestling Mat [330]

The cost of a wrestling mat is so great that few small clubs can afford to own one.  As we did not see our way

[Illustration:  Made of Bed Mattresses]

clear to purchase such a mat, I made one of six used bed mattresses (Fig. 1) purchased from a second-hand dealer.  I ordered a canvas bag, 12 ft. 3 in. by 12 ft. 9 in., from a tent company, to cover the mattresses.  The bag consisted of two pieces with the seam along each edge.  The mattresses were laid side by side and end to end and the bag placed on and laced up as shown in Fig. 2.  —­Contributed by Walter W. White, Denver, Colo.