Glass for gazing at ourselves and aliens

Mark Pendergrast has consulted 700 written sources, conducted 250 interviews and boiled down what he has learnt in this compendious survey of mirrors in history, from Turkish obsidian mirrors of 6000BC to the Hubble Space Telescope and beyond. The result is an odd mixture that lurches between cosmetic mirrors, the place of mirrors in magic and religion, stage illusions, houses of mirrors, whether animals can recognise themselves in mirrors, and much more besides. The book is organised in broadly chronological sequence, with six of the 12 chapters providing a history of reflecting telescopes, from Newton and Herschel through to radio telescopes whose huge dishes are "mirrors" capturing electromagnetic radiation beyond the limits of human vision.

One senses that this is where Pendergrast's real enthusiasm lies. The account is full of vivid anecdotes about the personal struggles and rivalries of astronomers as they compete to see ever farther into space and ever farther back in time. Pendergrast is excellent on the technical difficulties of manufacturing extremely large curved mirrors, whose shapes must be accurate to minute tolerances. The huge glass blanks can shatter if they are not cooled gradually over weeks or months. The process of grinding and polishing can absorb years of delicate handwork. One dropped tool or error of judgement can be fatal. (Pendergrast quotes optician David Hilyard's advice that "about ten minutes before you make your last mistake is when you should call a mirror done.") Interspersed with this astronomical history is a much more various assortment of chapters. At their least successful these come dangerously close to mere lists - of prehistoric cultures that had mirrors, of (non-scientific) books published in the 16th century with the word "mirror" in their titles. At their best, they offer short resumes of some mirror stories, which may be familiar enough but are worth retelling, such as John Dee and Edward Kelley's folie a deux with scrying mirrors, or how the French authorities smuggled Venetian glass-makers out of Murano to provide the expertise for what was to become the Manufacture Royale des Glaces at Saint-Gobain.

A chapter on mirrors in art might have gone further than it does, especially given the passionate debate about the possible use of concave mirrors by Renaissance painters, proposed by David Hockney in his Secret Knowledge (mentioned here just in a footnote). I remain sceptical about Hockney's "mirror-lens" theories, but there can be no question of the importance of flat mirrors for self-portraiture from Durer onwards (perhaps even earlier) or, I would suggest, of their central place in the formulation of the theory of linear perspective. Pendergrast touches these topics, but confines himself otherwise to an account of depictions of mirrors in paintings and ventures only a little way into their role in the conceptualisation and construction of pictorial space. (He also claims that Van Eyck's Arnolfini Portrait is in "perfect perspective", where the whole of Hockney's argument turns on the fact that it is coherent perspectivally in local areas, but not as a whole.) Pendergrast adds a final 13th chapter in which he makes a personal appearance, introduces us to some of the stranger places and characters that he visited during his research and tidies up a few odd topics that he has not managed to fit in elsewhere. One of these is the old and puzzling question of why mirrors reverse left-to-right but not top-to-bottom, which, strangely, Pendergrast says does not interest him much. The premise of the question is false, as Martin Gardner has pointed out: put a mirror on the floor, step (gingerly) onto it, and you will see yourself feet upwards. The conundrum assumes tacitly that the mirror hangs vertically, as most real mirrors do.

A second presupposition is that what is seen in the mirror is the human body, which is bilaterally symmetrical about a vertical plane (the left half "mirrors" the right half) but not about other planes. A sentient one-eyed sphere looking at itself in the mirror would have no trouble with the "puzzle". This line of reasoning might have led Pendergrast into deeper questions, of why and how mirror symmetry arises in the forms of animals.

But then his kaleidoscopic book could have bounced off in so many directions.

Philip Steadman is professor of urban and built form studies, University College London.