HUYGENS                                             , 902                                              HYDE PARK

fessor of natural history in the Royal School 01 Mines, London, and held that position till 1885. He was the first great teacher of biology by the laboratory method. With his assistant, Dr. Newell Martin, he published, in 1874, the famous Practical Biology, which was the means of introducing laboratory work in that department into the United States and some other countries. He was also interested in general education, and served a term as member of the London school board. He was the best popular exponent of science that the world has known, and in other respects a man of commanding intellectual power. He defended and explained Darwin's hypothesis of evolution with telling effect. Perhaps his greatest service was in promoting the advance toward intellectual honesty. Many of his works, like The Physical Basis of Life, Lay Sermons, Man's Place in Nature, Critiques and Addresses and Science and Culture are famous, and his controversial writings are also well known. His scientific researches fill four large octavo volumes, and his collected essays and books of a less technical character were published in 1892 in nine volumes. He died at Eastbourne, June 29, 1895. See Life and Letters by his son.

Huygens (koi'gens or hi'gĕm), Christian, "the Dutch Archimedes," was born at The Hague in 1629, and died there in 1695. A splendid ancestry, three years of university training and much travel combined to give him a liberal education. Most of his life was spent in Holland, but for 15 years following 1666 he worked in Paris under the patronage of Louis XIV and the French Academy of Sciences. His mathematical discoveries are important, but his chief distinction lies in the domain of physics, where he gave a general solution of the problem of the compound pendulum; invented the pendulum clock and applied it to the measurement of the acceleration of gravity at various parts of the earth's surface; discovered the laws governing the collision of bodies and centrifugal forces; suggested the wave-theory of light and applied it to the explanation of reflection, ordinary refraction and double refraction; and constructed the first powerful telescope of the refracting kind, discovered the rings of Saturn and its sixth satellite and improved the method of grinding and mounting lenses. All his work is characterized by practicability, clearness and elegance. A complete edition of his works has been (1888) published at The Hague.

Hy'acinth, the species of Hyacinthus, a genus of the lily family, containing about 30 species, most of which are natives of South Africa. The common hyacinth (H. orien-talis) is native to Syria, Asia Minor and Greece. It has long been cultivated and occurs in many varieties. Though a harbinger of spring, it is more of a hot-house than garden-flower.

Hy'acinthe, Pare ( par ê'a'sant'), is the former monastic name of Charles Loyson, who was born at Orléans, France, March 10, 1827. He studied at St. Sulpice, and in 1851, becoming a priest, he taught philosophy and theology at Avignon and at Nantes. Afterwards he became a Carmelite, came into notice as a powerful preacher, and gathered crowds from all ranks of society to hear him at the Madeleine and at Notre Dame in Paris. He was "silenced" because of unorthodox utterances; but, persisting in his course, he was excommunicated in 1869. One of the changes which he urged was that priests should be allowed to marry, and in 1872 he.married an American woman. In 1899 he established a congregation in Pans.

Hyderabad (hī'dêr-ă-bād') or Haidar'a-bad, capital of the Indian feudatory or native state, under British administration, of the same name, stands on the River Musi, 1,700 feet above the sea. It is one of the most important Mohammedan strongholds in India, and has many mosques. Wild and picturesque scenery surrounds the town, and the neighborhood is laid out in beautiful gardens and huge parks. Area of the state 82,698 square miles; population ir,i4i;i42; population of the city, with suburbs, 448,-466.

Hyder AH {hi'der ă'lë), ruler of Mysore and one of the greatest Mohammedan princes of India, was born in 1728. In 1749 his bravery at a siege brought him to the notice of one of the ministers of the maharajah. He soon became, in all but name, ruler of the kingdom. He conquered many adjoining states, and in 1766 ruled over 84,000 square miles. When, in 1772, he was attacked by the Mahrattas, he claimed English help, in accordance with the treaty in force between them. This was refused, and he became the bitter enemy of the British. When, in 1778, the English were at war with the French, he and his son, Tippoo Sahib, descended on them like a thunderbolt, wholly routed two commanders, and ravaged the country to within 40 miles of Madras. He was at last defeated in three battles by Sir Eyre Coote. He died in December, 1782.

Hyde Park, a famous London Park which covers, in the district of Westminster, 400 acres, reaching from the western end of London to Kensington Gardens. It was once part of the manor of Hyde, which belonged to Westminster Abbey. When the monasteries were dissolved under Henry VIII, these grounds came into possession of the crown, and in the reign of Charles II were (and remain) the great drive and walk of London.

Hyde Park, Mass., town in Norfolk County, on Neponset River, about four miles from Boston. It manufactures paper, morocco, cotton and woolen goods, dye-stuffs, looms, curled hair, chemicals and machinery. The town is a residential