The Strangest Piece of News

• BuyGalileo: Watcher of the Skies by David Wootton
  Yale, 328 pp, £25.00, October 2010, ISBN 978 0 300 12536 8
• BuyGalileo by J.L. Heilbron
  Oxford, 508 pp, £20.00, October 2010, ISBN 978 0 19 958352 2

In the winter of 1609-10, Galileo Galilei made a series of astronomical observations that added to the growing list of anomalies threatening the stability of the earth-centred Ptolemaic cosmos. His weak spyglass made mountains appear on the formerly pristine moon, resolved the Milky Way into innumerable stars, multiplied the number of objects in well-charted constellations and, most spectacularly, revealed four satellites orbiting Jupiter. Galileo swiftly published the narrative of these discoveries in the Sidereus Nuncius (‘Starry Messenger’), a quarto pamphlet of 60 pages, cramming in as many days’ observations of the Jovian satellites as he could without missing the deadline imposed by the most important opportunity for intellectual exchange in early modern Europe, the Frankfurt Book Fair. The pamphlet gestured to the possibility of using the satellites as a precise celestial clock, but relied on medieval merchant time to deliver its message. A fortnight before the fair, Galileo was still unsure of the title. On 13 March 1610, he sent the first, damp copy to his Tuscan patron and potential employer, Cosimo de’ Medici. The same day, the English ambassador to Venice, Sir Henry Wotton, sent a copy to James I, describing it as ‘the strangest piece of news (as I may justly call it)’ that he would ever have received ‘from any part of the world’. Most copies were probably sent over the Alps by Tommaso Baglioni, the book’s nominal publisher, or his boss, the excommunicated polemical printer Roberto Meietti, now in hiding behind various pseudonyms, after he’d acted as semi-official propagandist for Venice against Rome in a recent interdict controversy.