There aren’t many good books on the history of observational astronomy out there. The public perception of the lone astronomer standing vigil at the eyepiece is rapidly vanishing into the past.
In Search of Planet Vulcan reads like a good mystery novel. Few have heard the curious and intriguing tale of the search for inter-mercurial planets. Now a considered a scientific dead end, little is ever mentioned of the false pathways of science. But to the denizens of the late 19th century, Vulcan was real. Coins were even minted celebrating its supposed discovery. The book leads the readers through Herschels’ accidental discovery of Uranus, the mathematical triumph of the theoretical discovery of Neptune, and the eventual quest to discover a planet between the sun and Mercury to account for its unexplained motion. The hunt thickens as a French country doctor announces the observation of a spot transiting the sun. It was interesting to note that much of his calculations were done on a barn door! Although his instrustment used for the discovery was briefly mentioned, I would have liked to see more on how historical observations of the sun were done. Traditionally the projection method was the easiest (and safest!) way to observe the sun, but smoked glass was also used. Perhaps the authors didn’t want to be responsible for reviving dubious methods?
The book also lists several anomalous reports Vulcan (apparently, everyone was seeing strange spots on the sun in the 18th-19th century!) and climaxes with an expedition to the solar eclipse of 1878 in Wyoming. The plan was to sweep the area near the darkened sun for interlopers during the brief 2 minutes and 56 seconds of totality. None other than Thomas Edison also gets into the act, using his tasimeter to measure the temperature of the suns’ corona as a side line.
In Search of Planet Vulcan displays to true methodology of science. All to often, our acculmated knowledge is displayed as a rote set of facts; the torturous path to enlightenment is never seen. I heartily recomend this book to anyone interested in the scientific method or astronomical history. Or even anyone just looking for a good mystery!