[Illustration:  The Blade Is Cut Down]

useful.  To cut down the already worn blade would leave only a stump, but if the blade is fastened in a vise and the point B filed off until it is like C, Fig. 2, the projecting point A, Fig. 1, will sink into the handle as shown at D, Fig. 3, and the knife will be given a new lease of usefulness. — —­Contributed by James M. Kane, Doylestown, Pa.

** How to Make a Leather Spectacle Case [228]

The spectacle case shown in the accompanying illustration may be made of either calf or cow skin.  The calf skin, being softer, will be easier to work, but will not make as rigid a case as the cow skin.  If calf skin is to be used, secure a piece of modeling calf.  The extreme width of the case is 2-3/8 in. and the length 6-5/8 in.  Two pieces will be required of this size.  Put on the design before the two parts are sewed together.  First draw the design on paper, then prepare the leather.  Place the leather on a small non-absorbent surface, such as copper or brass, and moisten the back side with as much water as it will take and still not show on the face side.  Turn the leather, lay the design on the face, and hold it in place while both the outline and decoration are traced on the surface with a pencil or some tool that will make a sharp line without tearing the paper.

After the outlines are traced, go over the indentations a second time so as to make them sharp and distinct.  There are special modeling tools that can be purchased for this purpose, but a V-shaped nut pick, if smoothed with emery paper so that it will not cut the leather, will do just as well.

Take a stippling tool—­if no such tool is at hand, a cup-pointed nail set will do—­and stamp the background.  It is intended that the full design shall be placed on the back and the same design placed on the front as far as the material will allow.  Be careful in stamping not to pound so hard as to cut the leather.  A little rubbing on the point with emery will take off the sharpness always found on a new tool.

Having prepared the two sides, they may be placed together and sewed around the edges.

If cow hide is preferred, the same

[Illustration:  Two Designs of Cases]

method of treatment is used, but a form will need to be made and placed inside the case while the leather is drying to give it the right shape.  The form can be made of a stick of wood.

** Waterproofing a Wall [229]

The best way to make a tinted wall waterproof is to first use a material composed of cement properly tinted and with no glue in it—­one that will not require a glue size on the wall.  After this coating of cement is applied directly to the plaster, cover it completely with water enamel and, when dry, give the surface a thorough coating of varnish.  This will make a perfectly impervious covering, which steam, water or heat will not affect.  —­Contributed by Julia A. White, New York City.