Measuring Up: How Oliver Smoot Became a Standard Unit of Measurement
by Jenny Lacika; illus. by Anna Bron
Primary, Intermediate    MIT Press/Candlewick    32 pp.
9/25    9781536230123    $18.99

This unusual nonfiction picture book combines math, hijinks, and etymology—a subject amalgamation readers don’t encounter every day. In the mid-twentieth century, a group of MIT students wanted to measure the length of one of the bridges spanning the Charles River between Boston and Cambridge—without using a standard unit of measurement or a measuring tape. Instead, one of the students, 5’ 7” Oliver Smoot, repeatedly lay down with his feet pointing toward Boston and his head toward Cambridge until he traversed the bridge, a surprisingly exhausting endeavor that required his friends’ assistance. The length of each lie-down became a “smoot,” with the bridge’s distance totaling 364.4 smoots ± 1 ℇar (with ℇar allowing for minuscule human error). Every year afterward, MIT students repainted the smoot markings, and when a new bridge was constructed in the late 1980s, the sidewalk was scored with these same measurements, preserving the oddball tradition. The colorful digital illustrations signal a historical setting and amusingly incorporate mathematical symbols. Near the end of the engaging main text, a chart shows the smoot’s equivalents in other measurement systems, such as feet and millimeters, with a playful depiction of Oliver Smoot himself stretched out across the bottom row. Additional material discusses the MIT tradition of practical jokes, or “hacks,” with resources for further exploration. Also appended with more information about smoots, a bibliography, and a list of other measurements named for their inventors.

From the November/December 2025 issue of The Horn Book Magazine.