348. Neat Mode of Soldering
Cut out a piece of tinfoil the size of the surfaces to be soldered. Then dip a feather in a solution of sal ammoniac, and wet over the surfaces of the metal, then place them in their proper position with the tinfoil between. Put the metals thus arranged on a piece of iron hot enough to melt the foil. When cold the surfaces will be found firmly soldered together.
Who Never Tries Cannot Win the Prize.
349. Maps and Charts
Maps, charts, or engravings may be effectually varnished by brushing a very delicate coating of gutta-percha solution over their surface. It is perfectly transparent, and is said to improve the appearance of pictures. By coating both sides of important documents they can be kept waterproof and preserved perfectly.
350. Temperature of Furniture
Furniture made in the winter, and brought from a cold warehouse into a warm apartment, is very liable to crack.