Along with the Swann sale of Printed & Manuscript Americana on 17 September, PBA Galleries will sell Fine Books & Manuscripts, and on 17-18 September, Bloomsbury London will hold a Travel, Natural History, Polar, Maps & Atlases sale.
Expected highlights from PBA include a first edition (second issue) in English of Galileo's Dialogues (in Salusbury's Mathematical Collections and Translations, 1667), which is estimated at $30,000-40,000. A second edition of Newton's Principia (1713) could fetch between $18,000 and 25,000.
The Bloomsbury sale contains 801 lots, and I haven't time to browse through them all, so I've no idea what's in there.
