HADEN, SIR FRANCIS SEYMOUR, an etcher and writer on etching, born in London; was bred to medicine, and in 1857 became F.R.C.S.; in 1843 he took up etching as a pastime and has since pursued it with enthusiasm and conspicuous success; he has won medals in France, America, and England for the excellency of his workmanship, while his various writings have largely contributed to revive interest in the art; he is President of the Society of Painters, and in 1894 a knighthood was conferred upon him; b. 1818.

HADES (lit. the Unseen), the dark abode of the shades of the dead in the nether world, the entrance into which, on the confines of the Western Ocean, is unvisited by a single ray of the sun; originally the god of the nether world, and a synonym of PLUTO (q. v.).

HADITH, the Mohammedan Talmud, being a traditional account of Mahomet’s sayings and doings.

HADJI, a Mohammedan who has made his Hadj or pilgrimage to Mecca, and kissed the Black Stone of the CAABA (q. v.); the term is also applied to pilgrims to Jerusalem.

HADLEIGH (3), an interesting old market-town of Suffolk, on the Bret, 91/2 m.  W. of Ipswich; its cloth trade dates back to 1331; Guthrum, the Danish king, died here in 889, and Dr. Rowland Taylor suffered martyrdom in 1555.  Also a small parish of Essex, near the N. shore of the Thames estuary, 37 m.  E. of London, where in 1892 the Salvation Army planted their farm-colony.

HADLEY, JAMES, an American Greek scholar, and one of the American committee on the revision of the New Testament (1821-1872).

HADLEY, JOHN, natural philosopher; invented a 5 ft. reflecting telescope, and a quadrant which bears his name, though the honour of the invention has been assigned to others, Newton included (1682-1744).

HADRAMAUT (150), a dry and healthy plateau in Arabia, extending along the coast from Aden to Cape Ras-al-Hadd, nominally a dependency of Turkey.

HADRIAN, Roman emperor, born in Rome; distinguished himself under Trajan, his kinsman; was governor of Syria, and was proclaimed emperor by the army on Trajan’s death in A.D. 117; had troubles both at home and abroad on his accession, but these settled, he devoted the last 18 years of his reign chiefly to the administration of affairs throughout the empire; visited Gaul in 120, whence he passed over to Britain, where he built the great wall from the Tyne to the Solway; he was a Greek scholar, had a knowledge of Greek literature, encouraged industry, literature, and the arts, as well as reformed the laws (76-138).

HAECKEL, ERNST HEINRICH, an eminent German biologist, born at Potsdam; carried through his medical studies at Berlin and Vienna; early evinced an enthusiasm for zoology, and, after working for some time at Naples and Messina, in 1865 became professor of Zoology at Jena; here he spent a life of unceasing industry, varied only by expeditions to Arabia, India, Ceylon, and different parts of Europe in the prosecution of