[Illustration:  Volcano in Action]

earth about the sides until it is all covered excepting the top opening.  This is to keep all dampness away from the mixture to be placed within.

A fuse from a fire-cracker, or one made by winding some powder in tissue paper, is placed in the paper tube of the volcano with one end extending over the edge.  Get some potash from a drug store and be sure to state the purpose for which it is wanted, as there are numerous kinds of potash that will not be suitable.  An equal amount of sugar is mixed with the potash and placed in the paper tube.  On top of this put a layer of pure potash and on this pour some gun powder.  This completes the volcano and it only remains for the fuse to be lighted and action will begin with an explosion which sends fire, smoke and sparks upward.  Flames will follow and the lava pours down the sides of the mound.

** Wire Loop Connections for Battery Binding-Posts [449]

The trouble with battery binding post connections can be avoided by winding the bare end of the connecting wire around the binding-post screw and then back around its extending length as shown in the sketch.  Always screw down permanent connections with pliers.

[Illustration:  Loop]

** Melting Metal in the Flame of a Match [449]

The flame of an ordinary match has a much higher temperature than is generally known and will melt cast-iron or steel filings.  Try it by striking a match and sprinkle the filings through the flame.  Sputtering sparks like gunpowder will be the result of the melting metal.

** Russian Squirrels [449]

The squirrel slaughter of Russia amounts to 25,000,000 per year.

** Landscape Drawing Made Easy [449]

With this device anyone, no matter how little his artistic ability may be, can draw accurately and quickly any little bit of scenery or other subject and get everything in the true perspective and in the correct proportion.

[Illustration:  Drawing with the Aid of Reflecting Glasses]

No lens is required for making this camera-just a plain mirror set at an angle of 45 deg., with a piece of ordinary glass underneath, a screen with a peek hole and a board for holding the drawing paper.  The different parts may be fastened together by means of a box frame, or may be hinged together to allow folding up when carrying and a good tripod of heavy design should be used for supporting it.  In order to get the best results the screen should be blackened on the inside and the eyepiece should be blackened on the side next to the eye.  A piece of black cardboard placed over the end of the eyepiece and perforated with a pin makes an excellent peek hole.

In operation the rays of light coming from any given object, such as the arrow ab, strike the inclined mirror and are reflected downward.  On striking the inclined glass a portion of the light is again reflected and the rays entering the eye of the operator produce the virtual image on the paper as shown.  The general outlines may be sketched in quickly, leaving the details to be worked up later.  This arrangement may be used for interior work when the illumination is good.