[Heliopolis] (i. e. City of the Sun), in Egyptian On, one of the oldest and most sacred cities of Egypt; was situated about 10 m. N. of Cairo, on the eastmost branch of the Nile; it was the centre of Egyptian learning; Solon and Plato are said to have studied there, and Potiphar was one of its chief priests; the famous obelisk Pharaoh's Needle stands near; and Cleopatra's Needle, now on the Thames Embankment, was originally of this city. Also the name of Baalbec.
[Helios], the god of the sun, mistakenly identified with Apollo, but of an older dynasty, was the brother of [Selene] (q. v.) and [Eos] (q. v.); a god of the brood of the [Titans] (q. v.), and the source of light to both gods and men; he rises from the bosom of [Okeanos] (q. v.) in the morning, and loses himself in his dark abyss every evening.
[Heliotrope] or Bloodstone, a variety of quartz (chalcedony or jasper) of a deep green colour, with bright red spots. The finest specimens, which come from South Asia, are of fairly translucent chalcedony; those of jasper are opaque; they are used as seals, ring-stones, &c.
[Hell Fire], the infinite terror to a true man, the infinite misery which he never fails to realise must befall him if he come short in his loyalty to truth and duty.
[Hell Gate] or Hurl Gate, a narrow pass in the East River, between the city of New York and Long Island; at one time its hidden shoals and swift narrow current were dangerous to ships, but extensive blasting operations, completed in 1885, have greatly widened and cleared the pass.
[Hellas], the name of the abode of the ancient Greeks, and of greater extent than Greece proper.
[Helle], a maiden who, with her brother Phrixus, fled on the golden-fleeced ram to escape from the cruelty of her step-dame Ino, and fell into the strait called the Hellespont after her, in which she was drowned. See [Golden Fleece].
[Hellenists], originally Jews who would fain have seen Jewish thought and life more or less transformed in spirit as well as fashion after a Greek pattern; eventually those who by contact with Greek civilisation became Grecianised, and were open to learn as much from the civilisation of the Greeks as was consistent with the maintenance in their integrity of the principles of their own religion.
[Heller, Stephen], a distinguished pianist and composer, born at Pesth; made his début at nine, and by 17 had won a reputation throughout the great cities of Europe; in 1838 he settled in Paris, and gave himself to teaching and composition; he ranks beside Chopin as a master of technique; his works are almost entirely pianoforte pieces (1814-1888).
[Helmholtz, Hermann von], an eminent German scientist, born at Potsdam, Brandenburg; was first an army doctor, and in 1849 became professor of Physiology in Königsberg, and subsequently in Bonn and Heidelberg; in 1871 he became professor of Physics in Berlin; was ennobled, and in 1887 nominated head of the Charlottenburg Institute; to physiology he made contributions of great value on the various sense-organs, and to physics on the conservation of energy; but his most original work was done in connection with acoustics in its relation to optics; his published works include "Theory of Sound Sensations'" and "Sensations of Tone as a Physiological Basis for the Theory of Music" (1821-1894).