(Encyclopedia) chalk, mineral of calcium carbonate, similar in composition to limestone, but softer. It is characteristically a marine formation and sometimes occurs in great thickness; the chief…
(Encyclopedia) Chalkley, ThomasChalkley, Thomaschôˈklē [key], 1675–1741, Quaker mariner and missionary preacher, b. England. He made his home after 1701 in Philadelphia. He traded chiefly with the…
(Encyclopedia) Challenger, U.S. space shuttle. It exploded (Jan. 28, 1986) 73 seconds into its tenth flight, killing all seven crew members, including the first civilian in space, schoolteacher…
(Encyclopedia) Airy, Sir George Biddell, 1801–92, English astronomer. The son of a poor farmer, he distinguished himself as Senior Wrangler at Cambridge, where he was elected fellow of Trinity…
(Encyclopedia) Challenger expedition, British oceanographic expedition under the direction of the Scottish professor Charles Wyville Thompson and the British naturalist Sir John Murray. Taking place…
(Encyclopedia) Challoner, RichardChalloner, Richardchălˈənər [key], 1691–1781, English Roman Catholic prelate. Brought up a Protestant, he became a Roman Catholic in his teens and was ordained in…
(Encyclopedia) Chalmers, ThomasChalmers, Thomaschäˈmərz, chôˈ– [key], 1780–1847, Scottish preacher, theologian, and philanthropist, leader of the Free Church of Scotland. His preaching and his…
