The fate of a rare fourteenth-century astrolabe quadrant — a kind of medieval pocket calculator — hangs in the balance while the British Museum in London tries to raise £350,000 (US$700,000) to ...

The bronze astrolabe, originating from the 9th and 10th century Baghdad, forms part of the Sotheby’s ‘Arts of the Islamic World and India’ sale in London. In the marvellous halls of Sotheby's, London, ...