a vast tract of barren rocks and burning sands, extending from Syene in Upper Egypt, to Geon, the capital of Berber in Nubia. As Syene is in latitude 24° 0' 45" north, and Geon in latitude 17° 37' 22", the length of this desert from north to south is 6° 3' 23", or upwards of 420 English miles. Its breadth from east to west has not, as far as we know, been precisely ascertained.