The present uncertainty consists largely as to how high-tension steel
will endure the manipulation usual with iron without injury. A few
experiments were recently made by the writer on riveted struts of both
mild and hard steel, which had been punched, straightened, and riveted,
as usual with iron, but no indication of deterioration was found.

Steel castings are now made entirely trustworthy for tensile working
stresses of 10,000 to 15,000 pounds per square inch. In some portable
machinery, an intermittent tensile stress is applied of 15,000 pounds,
sometimes rising to 20,000 pounds per square inch of section, without any
evidence of weakness.

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Equal volumes of amyl alcohol (rectified fusel oil) and pure concentrated
hydrochloric acid, shaken together in a test tube, unite to form a single
colorless liquid; if one volume of benzine (from petroleum) be added to
this, and the tube well shaken, the contents will soon separate into
_three_ distinct colorless fluids, the planes of demarkation being
clearly discernible by transmitted light. Drop into the tube a particle
of "acid magenta;" after again shaking the liquids together, the lower
two zones will present different shades of red, while the supernatant
hydrocarbon will remain without color.

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