The Thermit heating and welding compound is coming to the front as a ready and practical method of effecting economy in various ways in shop practice.

One great saving brought about by its use is in the repairing of broken locomotive frames, which can be done without removing the wheels or other parts, as the welding is done with everything in place. The welded spot is as strong as the original piece itself, and in cases where the reinforcement or so-called "collar " can be left around the weld, it is really stronger than the original piece. The heat of the applied Thermit melts the broken ends, fusing them with itself; Thermit supplies the missing metal, the weld taking as large a reinforcement as the mold is made to permit.

Broken cog teeth can be recast on a wheel with Thermit steel; cracked driving wheels can be neatly mended in place, and an infinite number of useful and economical repairs made, that will keep down the scrap pile. Its uae will give large resulant economy in time, patience and money.

Thermit itself is only a mixture of granulated aluminum and iron oxide, the combustion, or reaction being started by means of an ignition powder. Thermit mit itself can be thrown into the fire without igniting, as nothing less than the heat of liquid steel will cause it to burn.

As the combustion of the aluminum is supported entirely by the oxygen of the oxide, the reaction is entirely local, being confined to the crucible, there being no explosion nor any gas resulting. The reaction is complete in a few seconds and the molten metal is instantly ready to run into the mold about the broken part; the iron, sepaiated out from the oxide, makes a very good mild steel with only 0.1 carbon.

Thermit is now being manufactured in this country under the Dr. Hans Goldechmidt patents. The apparatus necessary for operations with Thermit is simple and inexpensive, and the process can be employed by any practical mechanic.