Page:Popular Mechanics 1928 11.pdf/35

 vantage to melt glue in the manufacture of paper boxes, shoes, furniture, books, pianos and automobiles. It is also the ideal means of melting lead and tin, as well as solder, babbitt and similar alloys. The electric melting pot maintains the correct temperature automatically, without the danger of burning and without slag.



The electric welding of steel and other metals began half a century ago, but it has lately assumed many new forms and has been applied to a great variety of purposes. One of its newer feats is to add metal to rails where they are worn at the joints without removing them from the track. Various automatic welding machines have come into use, especially for welding the seams of tubes and pipes. Electric arc welding has had sensational success during the last two or three years as a substitute for riveting in the construction of steel-frame buildings, and also in shipbuilding.

Another important application of welding is in the construction of airplane fuselages. Metal has practically displaced wood in American-built commercial planes because of the superior strength of special alloy tubing, with no appreciable difference in the weight of the completed machine. Tests of properly welded joints invariably show that the weld is stronger than the rest of the material.

"Heat it electrically." is the new watchword of industry.



Orchardists in South Africa have been calling upon California for supplies of a certain species of beetle that devours the troublesome mealy bugs attacking trees in Africa. Growers are attempting to cultivate the beetles and raise a large army of them against the mealy bugs.

