Create fantastic jewelry using gemstones and sparkling metals.
Measures, marks, and etches units on side of glass tube or similar measuring devices, using calibrating device and solution of hydrofluoric acid: Fills tube with specified quantity of mercury and marks meniscus of mercury with special pen. Covers tube with wax. Positions tube in calibrating device, aligns needle guide with calibrated ruler, and turns locknut to hold guide in place so that exact measurement can be marked, starting from meniscus. Turns handwheel that moves needle in back-and-forth motion to remove wax and expose glass to be etched with acid. Realigns needle guide to next unit to be marked and continues sequence until tube is calibrated. Removes tube from calibrating device and dips it into solution of hydrofluoric acid so that acid will permanently etch area of glass not covered with wax. Rinses tube in cold water to remove excess acid and in hot water to remove wax.