First procure a small piece of thin sheet aluminium, say about 1 in. square, and roll it into a little coil; next procure a wooden penholder and place the roll of aluminium in the hollow end of the penholder, leaving about one-half out, and give the end that is out of the holder a light blow or two to flatten it. Clean the alumininium article at the place of the joint by rubbing with fine emery cloth, or by scraping with a knife ; heat the article to be soldered to the melting point of the solder in any convenient way, say on the top plate of a kitchen range, or over a Bunsen burner with a piece of sheet iron placed thereon. Then place it on the table or work-bench on sheet asbestos to prevent burning the table-, and when hot, sprinkle on the flux ;iinl rub with the little aluminium tool, which tins the surface very easily. While the article is still hot apply the solder, and guide the flow with the narrow edge of the tool; then remove the article and allow it to cool to produce a very strong and perfect joint. No soldering iron, blowpipe, blow-lamp, or special apparatus is required by this method. Here is a recipe for a special hard aluminimn solder for cycle, or any special work. Aluminium, 70 per cent.; tin, 20 per cent.; and silver, 10 per cent.

This hard solder is worked with the same process as that described above, but requires a little higher temperature.