The reason metric conversion (Feb. 21) never worked in the U.S. is that the government in the 1970s encouraged only metric labeling, not metric packaging. Milk, for example, continued to be marketed in quart containers while the label read in fractions of liters. "Honey, would you stop off at the market and pick up a .946-liter container of milk and .4536 kilograms (a pound) of hamburger?" No wonder nobody wanted to deal with metrics.
Had manufacturers actually packaged items in metric terms, you bet everyone would be buying liters of milk, gasoline, etc., instead of English system fractions. Who's going to ask for 1.058 quarts? I suspect the main reason manufacturers didn't go for metric is that by sheer accident of arithmetic, a liter is a bit more than a quart. If a liter had measured a bit under a quart, there would be a rush to convert and give the customers less.
Marina del Rey
* The engineers in the Mechanical Systems Development Section enjoyed the article about metrics at JPL. We do feel it is important to note that the poster shown on Page 2 ("Metrics Is a Perfect 10") is printed on a 91.44-centimeters by 60.96-centimeters piece of paper. In real units that measures in at 24 inches by 36 inches.
Isn't it nice to know the metrics conversion office is setting such a fine example?