An employee at Sotheby's auction house holds a 14th century astrolabe, an astronomical instrument used by astronomers to calculate the position of the sun and prominent stars, valued at 600,000 to 800,000 sterling pounds, as part of the auction house's forthcoming Arts of the Islamic World and India sale on March 31, in London, Monday March 29, 2021. (Dominic Lipinski/PA via AP)