The Haunted Observatory: Curiosities from the Astronomer's Cabinet

William Herschel arrived in Hanoverian England as a penniless refugee who first eked out a meagre living as a professional musician. In 1766, his fortunes changed dramatically when his great talent landed him the prime position of organist at the Octagon Chapel in Bath. When the cash from concerts, teaching and church services started to roll in, he developed a new interest, astronomy, eventually becoming the best telescope maker and the best observer in the world.

Herschel was the first astronomer to attempt systematic observations of the starry realms beyond the solar system. To fathom immensity he compiled the first catalogues of nebulae, and commenced stellar astronomy. In all this he and his sister Caroline were pioneers.

Observational astronomy changed for good on 13 March 1781, when Herschel had his first sighting of a new planet, Uranus. This was a great triumph for which he received a good pension from George III. Herschel's planet launched astronomy on a new track in which telescope development and a systematic approach to observation would slowly open up the solar system and the universe beyond.

Richard Baum has long had a deep interest in the history of astronomical discovery in the century and a half after the finding of Uranus. The Haunted Observatory is a collection of 11 essays that recount false trails, wild goose chases and unresolved mysteries, trawled from the period when astronomers had little knowledge of the physical nature of the objects they recorded. The stories show how, time and again, speculation or overinterpretation of the observations led to bizarre programmes of research.

The planet Venus is shrouded in dense cloud, which led some observers to imagine they could see the peaks of a mountain chain up to 24 miles high poking through the cloud deck. Although Herschel did not fall for that one, plenty of observers became believers in the Himalayas of Venus.

In completing the inventory of the solar system, observers could be sidetracked by attempting to find a system of natural satellites orbiting the Moon. Or perhaps they got sucked into a campaign to discover bright objects close to the Sun. An apparent ring around Neptune beguiled astronomers for decades. But the real rings, which were discovered in 1989, could not possibly have been glimpsed through a Victorian telescope.

You will not find any of the enigmas selected by Baum in a textbook for the simple reason that he has sifted through fragments that ended up discarded on the observatory floor as dead ends. What is striking is the passion with which astronomers could pursue a fruitless quest, propelled by no more than vague descriptions of occurrences that remained unexplained. The satellites of the Moon turned out to be defects of the photographic plates.

For much of the historical period that is the focus of this book, astrophysics scarcely existed, most observers were non-professional, and information on the distance scale did not exist. The astronomers launched into uncharted waters, so it is scarcely surprising that they sometimes jumped to the wrong conclusion. This is the harvest of a quiet eye in which Baum nicely distils a romantic spirit of cosmic enquiry that ignored rationality and scepticism. The book's origin as a series of unconnected essays is, however, rather obvious to the reader who is conducted on a tour akin to a random walk across the vault of the heavens.