When soldering, care must be taken to have the parts to be soldered thoroughly clean.  Any grease or foreign matter will prevent the solder from running properly.  On a piece of slate slab, heavy glass or other hard, nonabsorbent substance that is clean, put a little water and grind a lump of borax around until the resultant is like thin cream.  Thoroughly clean the parts that are to be soldered by scraping with a knife, and do not touch with the fingers afterward.  Place a piece of thin silver solder between the parts after having coated them and the solder with the borax.  Use a pair of tweezers to pick up the solder.  Hold the parts firmly together and apply heat—­slowly at first until all moisture has been expelled and the borax crystallized, after which the flame may be applied more directly and the parts brought to a soldering heat.  An alcohol flame will do.  Heat applied too quickly will throw off the solder and spoil the attempt.

There are various ways of finishing the metal.  It may be polished by means of powdered pumice, chalk or charcoal, and then treated with a coat of French varnish diluted ten times its volume in alcohol.  Another popular way is to give the background a bluish-green effect by brushing it over a great many times, after it has been cleaned, with a solution composed of muriate of ammonia, 1 part; carbonate of ammonia, 3 parts; water, 24 parts.  The whole may then be treated with French varnish to preserve the colors.

** How to Make an Easel [415]

A strong and substantial easel may be made at home with very little expense and no great difficulty.

Smooth down with a plane, four pieces of pine, 1 in. thick, 4 in. wide and 4 ft. long, until suitable for legs.  Make three cross-pieces, Fig. 1, and join the legs with them as shown in Fig. 2.  With an auger bore a hole in each leg about 3 in. from the bottom, and fit into each a little peg, Fig. 2, for the picture to rest on.  The peg should be of hardwood so it will not break.

Cut the handle from an old broom, measure off the right length, and put a hinge on one end.  Fasten this leg on the second cross-piece, thus forming a support for the two front legs, Fig. 3.  The easel may be finished according to the individual taste.  It may be sandpapered and stained and varnished, or painted in some pretty tint, or, if preferred, may be enameled.  —­Contributed by G. J. Tress.

[Illustration:  Details of Easel Construction]

** How to Make a Wind Propeller [415]

A wind propeller may be constructed with four old bicycle wheels arranged with shafts pretty much like the shafts of a hand-propelled cart.  The platform is flatter, however, and the body one tier so that it is lower.  A framework of wood is built at M and this is a support

[Illustration:  Wind Propeller]