This book succinctly traces the history of the metric system from early modern proposals of decimal measures, to the birth of the system in Revolutionary France, through its formal international adoption under the supervision of an international General Committee of Weights and Measures (CGPM), to its later expansion into the International System of Units (SI), currently formulated entirely in terms of physical constants. The wide range of human activities that employ weights and measures, from practical commerce to esoteric science, influenced both the development and the diffusion of the metric system. The roles of constants of nature in the formulation of the 18th-century metric system and in the 21st-century reformulation of the SI are described. Finally, the status of the system in the United States, the last major holdout against its everyday use, is also discussed.

The intriguing tale of why the United States has never adopted the metric system, and what that says about us. The American standard system of measurement is a unique and odd thing to behold with its esoteric, inconsistent standards: twelve inches in a foot, three feet in a yard, sixteen ounces in a pound, one hundred pennies to the dollar. For something as elemental as counting and estimating the world around us, it seems like a confusing tool to use. So how did we end up with it? Most of the rest of the world is on the metric system, and for a time in the 1970s America appeared ready to make the switch. Yet it never happened, and the reasons for that get to the root of who we think we are, just as the measurements are woven into the ways we think. John Marciano chronicles the origins of measurement systems, the kaleidoscopic array of standards throughout Europe and the thirteen American colonies, the combination of intellect and circumstance that resulted in the metric system's creation in France in the wake of the French Revolution, and America's stubborn adherence to the hybrid United States Customary System ever since. As much as it is a tale of quarters and tenths, it is a human drama, replete with great inventors, visionary presidents, obsessive activists, and science-loving technocrats. Anyone who reads this inquisitive, engaging story will never read Robert Frost's line “miles to go before I sleep” or eat a foot-long sub again without wondering, Whatever happened to the metric system?