This is an easy to read, compelling history of the North Atlantic obsession with finding a way to measure 0.1 seconds. This isn’t, however, just about measurement. It’s about Modernity and time, the movement from qualitative to quantitative, the absorption of philosophy moral psychology (Aristotle, Stoics, Epicureans) into nineteenth-century science. Canales is a brilliant historian of more than science, but of philosophy, Modernity, technology, and all of their entanglements.