by Philip Ball
April 2, 2008
“The British Museum needs 350,000 pounds to secure this astrolabe.
The fate of a fourteenth-century pocket calculator is hanging in the balance between museum ownership and private sale.
The device is a brass astrolabe quadrant that opens a new window on the mathematical and astronomical literacy of the Middle Ages, experts say. It can tell the time from the position of the Sun, calculate the heights of tall objects, and work out the date of Easter.”