A Wand for the Meter Reader; October 1993; Scientific American Magazine; by Joshua Shapiro; 1 Page(s)
When gaslights were introduced into homes and businesses in the late 19th century, suppliers billed according to the number of lamps at the establishment. After heating and cooking made gas consumption more variable, the bellows meter was developed. A complicated mechanism, this instrument originally used a pair of inflatable sheep bladders linked by crankshaft and connecting rods to ratchet- and gear-driven dials.
Some 100 years later the bellows have been changed to rubber, but the same ungainly design is still in use all over the world. The mundane meter is the most common home appliance that is not directly purchased by consumers. More than 10 million are sold annually to gas utilities, supporting a $700-million-a-year market. But not for much longer. These unsightly castiron lawn ornaments may be supplanted by a new electronic version developed after five years of work by government boffins Down Under.