Homage to the man who turned feeble-and-far-between harbor lights into a global multitude of brilliant beacons.
Levitt (History/Univ. of Mississippi) trains the spotlight on Augustin Fresnel (1788–1827), a French civil engineer whose early-19th-century optics experiments demonstrated that light traveled in waves, challenging leading scientists who defended particle theory. He went on to develop the Fresnel lens system, a series of triangular-shaped glass prisms in circular arrays, each prism angled to refract light into a single strong beam that projected to the horizon and beyond. Fresnel died of tuberculosis at age 39, but his legacy survived. Fresnel lenses would eventually replace the far-less-efficient lighthouses that shined light reflected from silver-mirrored parabola-shaped enclosures. However, Fresnel lenses were costly and required quality glass and precision grinding at a time in Paris when a horse powered the glassmaker’s machines. Levitt’s scrupulous scholarship and contextual setting serve readers well. She reminds us of how dangerous the sailor’s life was and how low-intensity reflectors fell far short of the brightness and depth that ships required to prevent their foundering. The author also neatly contrasts Britain with France and America. Britain was ahead of France in Fresnel’s time, already replacing horses with steam power and soon competing with the French in manufacturing Fresnel lenses. Meanwhile, America remained decades behind, thanks to a bureaucracy in which lighthouse management was in the hands of a treasury department auditor who would not use the Fresnel lenses. That changed in the 1840s with a new generation of progressives and the presidency of James Polk, ushering in massive lighthouse building with Fresnel installations—until the Civil War, when the Confederacy hid or destroyed many of them.
Thanks to radio, radar and GPS, the “golden era” of lighthouses is over, but Levitt’s century-and-a-half saga of an innovator whose ideas were at times fostered, at times thwarted, by politicians or leading scientists, is most welcome.