Boston-born Thomas Whittemore, a friend of Turkish reformer Atatürk, uncovered the gems that had been hidden for 500 years.If Istanbul’s Hagia Sophia gets turned into a mosque, as many expect it will, its precious Byzantine mosaic icons are likely to be covered up during Muslim prayers. The mosaics were plastered over for centuries when the former cathedral of the Church of Constantinople served as a place of Muslim worship. On July 10, in an address to the nation, Turkey’s President, Recep Tayyip Erdoğan, announced that Hagia Sophia would be reopened for Muslim worship on July 24. The Turkish Council of...