Part 17

HEUGLIN, THEODOR VON (1824-1876), German traveller in north-east Africa, was born on the 20th of March 1824 at Hirschlanden near Leonberg in Wurttemberg. His father was a Protestant pastor, and he was trained to be a mining engineer. He was ambitious, however, to become a scientific investigator of unknown regions, and with that object studied the natural sciences, especially zoology. In 1850 he went to Egypt where he learnt Arabic, afterwards visiting Arabia Petraea. In 1852 he accompanied Dr Reitz, Austrian consul at Khartum, on a journey to Abyssinia, and in the next year was appointed Dr Reitz's successor in the consulate. While he held this post he travelled in Abyssinia and Kordofan, making a valuable collection of natural history specimens. In 1857 he journeyed through the coast lands of the African side of the Red Sea, and along the Somali coast. In 1860 he was chosen leader of an expedition to search for Eduard Vogel, his companions including Werner Munzinger, Gottlob Kinzelbach, and Dr Hermann Steudner. In June 1861 the party landed at Massawa, having instructions to go direct to Khartum and thence to Wadai, where Vogel was thought to be detained. Heuglin, accompanied by Dr Steudner, turned aside and made a wide detour through Abyssinia and the Galla country, and in consequence the leadership of the expedition was taken from him. He and Steudner reached Khartum in 1862 and there joined the party organized by Miss Tinne. With her or on their own account, they travelled up the White Nile to Gondokoro and explored a great part of the Bahr-el-Ghazal, where Steudner died of fever on the 10th of April 1863. Heuglin returned to Europe at the end of 1864. In 1870 and 1871 he made a valuable series of explorations in Spitsbergen and Novaya Zemlya; but 1875 found him again in north-east Africa, in the country of the Beni Amer and northern Abyssinia. He was preparing for an exploration of the island of Sokotra, when he died, at Stuttgart, on the 5th of November 1876. It is principally by his zoological, and more especially his ornithological, labours that Heuglin has taken rank as an independent authority.

His chief works are _Systematische Ubersicht der Vogel Nordost-Afrikas_ (1855); _Reisen in Nordost-Afrika, 1852-1853_ (Gotha, 1857); _Syst. Ubersicht der Saugetiere Nordost-Afrikas_ (Vienna, 1867); _Reise nach Abessinien, den Gala-Landern_, &c., _1861-1862_ (Jena, 1868); _Reise in das Gebiet des Weissen Nil_, &c. _1862-1864_ (Leipzig, 1869); _Reisen nach dem Nordpolarmeer, 1870-1871_ (Brunswick, 1872-1874); _Ornithologie von Nordost-Afrika_ (Cassel, 1869-1875); _Reise in Nordost-Afrika_ (Brunswick, 1877, 2 vols.) A list of the more important of his numerous contributions to _Petermann's Mitteilungen_ will be found in that serial for 1877 at the close of the necrological notice.

HEULANDITE, a mineral of the zeolite group, consisting of hydrous calcium and aluminium silicate, H4CaAl2(SiO3)6 + 3H20. Small amounts of sodium and potassium are usually present replacing part of the calcium. Crystals are monoclinic, and have a characteristic coffin-shaped habit. They have a perfect cleavage parallel to the plane of symmetry (M in the figure), on which the lustre is markedly pearly; on other faces the lustre is of the vitreous type. The mineral is usually colourless or white, sometimes brick-red, and varies from transparent to translucent. The hardness is 3(1/2)-4, and the specific gravity 2.2.

[Illustration]

Heulandite closely resembles stilbite (q.v.) in appearance, and differs from it chemically only in containing rather less water of crystallization. The two minerals may, however, be readily distinguished by the fact that in heulandite the acute positive bisectrix of the optic axes emerges perpendicular to the cleavage. Heulandite was first separated from stilbite by A. Breithaupt in 1818, and named by him euzeolite (meaning beautiful zeolite); independently, in 1822, H. J. Brooke arrived at the same result, giving the name heulandite, after the mineral collector, Henry Heuland.

Heulandite occurs with stilbite and other zeolites in the amygdaloidal cavities of basaltic volcanic rocks, and occasionally in gneiss and metalliferous veins. The best specimens are from the basalts of Berufjord, near Djupivogr, in Iceland and the Faroe Islands, and the Deccan traps of the Sahyadri mountains near Bombay. Crystals of a brick-red colour are from Campsie Fells in Stirlingshire and the Fassathal in Tirol. A variety known as beaumontite occurs as small yellow crystals on syenitic schist near Baltimore in Maryland.

Isomorphous with heulandite is the strontium and barium zeolite brewsterite, named after Sir David Brewster. The greyish monoclinic crystals have the composition H4(Sr, Ba, Ca)Al2(SiO3)6 + 3H2O, and are found in the basalt of the Giant's Causeway in Co. Antrim, and with harmotome in the lead mines at Strontian in Argyllshire. (L. J. S.)

HEUSCH, WILLEM, or GUILLIAM DE, a Dutch landscape painter in the 17th century at Utrecht. The dates of this artist's birth and death are unknown. Nothing certain is recorded of him except that he presided over the gild of Utrecht, whilst Cornelis Poelemburg, Jan Both and Jan Weenix formed the council of that body, in 1649. According to the majority of historians, Heusch was born in 1638, and was taught by Jan Both. But each of these statements seems open to doubt; and although it is obvious that the style of Heusch is identical with that of Both, it may be that the two masters during their travels in Italy fell under the influence of Claude Lorraine, whose "Arcadian" art they imitated. Heusch certainly painted the same effects of evening in wide expanses of country varied by rock formations and lofty thin-leaved arborescence as Both. There is little to distinguish one master from the other, except that of the two Both is perhaps the more delicate colourist. The gild of Utrecht in the middle of the 17th century was composed of artists who clung faithfully to each other. Poelemburg, who painted figures for Jan Both, did the same duty for Heusch. Sometimes Heusch sketched landscapes for the battlepieces of Molenaer. The most important examples of Heusch are in the galleries of the Hague and Rotterdam, in the Belvedere at Vienna, the Stadel at Frankfort and the Louvre. His pictures are signed with the full name, beginning with a monogram combining a G (for Guilliam), D and H. Heusch's etchings, of which thirteen are known, are also in the character of those of Both.

After Guilliam there also flourished at Utrecht his nephew, Jacob de Heusch, who signs like his uncle, substituting an initial J for the initial G. He was born at Utrecht in 1657, learnt drawing from his uncle, and travelled early to Rome, where he acquired friends and patrons for whom he executed pictures after his return. He settled for a time at Berlin, but finally retired to Utrecht, where he died in 1701. Jacob was an "Arcadian," like his relative, and an imitator of Both, and he chiefly painted Italian harbour views. But his pictures are now scarce. Two of his canvases, the "Ponte Rotto" at Rome, in the Brunswick Gallery, and a lake harbour with shipping in the Lichtenstein collection at Vienna, are dated 1696. A harbour with a tower and distant mountains, in the Belvedere at Vienna, was executed in 1699. Other examples may be found in English private galleries, in the Hermitage of St Petersburg and the museums of Rouen and Montpellier.

HEVELIUS [HEVEL or HOWELCKE], JOHANN (1611-1687), German astronomer, was born at Danzig on the 28th of January 1611. He studied jurisprudence at Leiden in 1630; travelled in England and France; and in 1634 settled in his native town as a brewer and town councillor. From 1639 his chief interest became centred in astronomy, though he took, throughout his life, a leading part in municipal affairs. In 1641 he built an observatory in his house, provided with a splendid instrumental outfit, including ultimately a tubeless telescope of 150 ft. focal length, constructed by himself. It was visited, on the 29th of January 1660, by John II. and Maria Gonzaga, king and queen of Poland. Hevelius made observations of sun-spots, 1642-1645, devoted four years to charting the lunar surface, discovered the moon's libration in longitude, and published his results in _Selenographia_ (1647), a work which entitles him to be called the founder of lunar topography. He discovered four comets in the several years 1652, 1661, 1672 and 1677, and suggested the revolution of such bodies in parabolic tracks round the sun. On the 26th of September 1679, his observatory, instruments and books were maliciously destroyed by fire, the catastrophe being described in the preface to his _Annus climactericus_ (1685). He promptly repaired the damage, so far as to enable him to observe the great comet of December 1680; but his health suffered from the shock, and he died on the 28th of January 1687. Among his works were: _Prodromus cometicus_ (1665); _Cometographia_ (1668); _Machina coelestis_ (first part, 1673), containing a description of his instruments; the second part (1679) is extremely rare, nearly the whole issue having perished in the conflagration of 1679. The observations made by Hevelius on the variable star named by him "Mira" are included in _Annus climactericus_. His catalogue of 1564 stars appeared posthumously in _Prodromus astronomiae_ (1690). Its value was much impaired by his preference of the antique "pinnules" to telescopic sights on quadrants. This led to an acrimonious controversy with Robert Hooke. In an _Atlas_ of 56 sheets, corresponding to his catalogue, and entitled _Firmamentum Sobiescianum_ (1690), he delineated seven new constellations, still in use. Hevelius had his book printed in his own house, at lavish expense, and himself not only designed but engraved many of the plates.

See J. H. Westphal, _Leben, Studien, und Schriften des Astronomen Johann Hevelius_ (1820); C. B. Lengnich, _Anekdoten und Nachrichten_ (1780); _Allgemeine deutsche Biographie_ (C. Bruhns); J. B. J. Delambre, _Histoire de l'astronomie moderne_, ii. 471; J. F. Weidler, _Historia astronomiae_, p. 486; F. Baily's edition of the Catalogue of Hevelius, _Memoirs Roy. Astr. Society_, xiii. (1843); R. Wolf, _Geschichte der Astronomie_, p. 396; J. C. Poggendorff, _Biog.-lit. Handworterbuch_. For an account of the epistolary remains of Hevelius, see C. G. Hecker, _Monatl. Correspondenz_, viii. 30; also _Astr. Nachrichten_, vols. xxiii., xxiv. (A. M. C.)

HEWETT, SIR PRESCOTT GARDNER, Bart. (1812-1891), British surgeon, was born on the 3rd of July 1812, being the son of a Yorkshire country gentleman. He lived for some years in early life in Paris, and started on a career as an artist, but abandoned it for surgery. He entered St George's Hospital, London (where his half-brother, Dr Cornwallis Hewett, was physician from 1825 to 1833) becoming demonstrator of anatomy and curator of the museum. He was the pupil and intimate friend of Sir B. C. Brodie, and helped him in much of his work. Eventually he rose to be anatomical lecturer, assistant-surgeon and surgeon to the hospital. In 1876 he was president of the College of Surgeons; in 1877 he was made serjeant-surgeon extraordinary to Queen Victoria, in 1884 serjeant-surgeon, and in 1883 he was created a baronet. He was a very good lecturer, but shrank from authorship; his lectures on _Surgical Affections of the Head_ were, however, embodied in his treatise on the subject in Holmes's _System of Surgery_. As a surgeon he was always extremely conservative, but hesitated at no operation, however severe, when convinced of its expediency. He was a perfect operator, and one of the most trustworthy of counsellors. He died on the 19th of June 1891.

HEWITT, ABRAM STEVENS (1822-1903), American manufacturer and political leader, was born in Haverstraw, New York, on the 31st of July 1822. His father, John, a Staffordshire man, was one of a party of four mechanics who were sent by Boulton and Watt to Philadelphia about 1790 to set up a steam engine for the city water-works and who in 1793-1794 built at Belleville, N.J., the first steam engine constructed wholly in America; he made a fortune in the manufacture of furniture, but lost it by the burning of his factories. The boy's mother was of Huguenot descent. He graduated with high rank from Columbia College in 1842, having supported himself through his course. He taught mathematics at Columbia, and in 1845 was admitted to the bar, but, owing to defective eyesight, never practised. With Edward Cooper (son of Peter Cooper, whom Hewitt greatly assisted in organizing Cooper Union, and whose daughter he married) he went into the manufacture of iron girders and beams under the firm name of Cooper, Hewitt & Co. His study of the making of gun-barrel iron in England enabled him to be of great assistance to the United States government during the Civil War, when he refused any profit on such orders. The men in his works never struck--indeed in 1873-1878 his plant was run at an annual loss of $100,000. In politics he was a Democrat. In 1871 he was prominent in the re-organization of Tammany after the fall of the "Tweed Ring"; from 1875 until the end of 1886 (except in 1879-1881) he was a representative in Congress; in 1876 he left Tammany for the County Democracy; in the Hayes-Tilden campaign of that year he was chairman of the Democratic National Committee, and in Congress he was one of the House members of the joint committee which drew up the famous Electoral Count Act providing for the Electoral Commission. In 1886 he was elected mayor of New York City, his nomination having been forced upon the Democratic Party by the strength of the other nominees, Henry George and Theodore Roosevelt; his administration (1887-1888) was thoroughly efficient and creditable, but he broke with Tammany, was not renominated, ran independently for re-election, and was defeated. In 1896 and 1900 he voted the Republican ticket, but did not ally himself with the organization. He died in New York City on the 18th of January 1903. In Congress he was a consistent defender of sound money and civil service reform; in municipal politics he was in favour of business administrations and opposed to partisan nominations. He was a leader of those who contended for reform in municipal government, was conspicuous for his public spirit, and exerted a great influence for good not only in New York City but in the state and nation. His most famous speech was that made at the opening of the Brooklyn Bridge in 1883. He was a terse, able and lucid speaker, master of wit and sarcasm, and a fearless critic. He gave liberally to Cooper Union, of which he was trustee and secretary, and which owes much of its success to him; was a trustee of Columbia University from 1901 until his death, chairman of the board of trustees of Barnard College, and was one of the original trustees, first chairman of the board of trustees, and a member of the executive committee of the Carnegie Institution.

HEWLETT, MAURICE HENRY (1861- ), English novelist, was born on the 22nd of January 1861, the eldest son of Henry Gay Hewlett, of Shaw Hall, Addington, Kent. He was educated at the London International College, Spring Grove, Isleworth, and was called to the bar in 1891. From 1896 to 1900 he was keeper of the land revenue records and enrolments. He published in 1895 two books on Italy, _Earthwork out of Tuscany_, and (in verse) _The Masque of Dead Florentines_. _Songs and Meditations_ followed in 1897, and in 1898 he won an immediate reputation by his _Forest Lovers_, a romance of medieval England, full of rapid movement and passion. In the same year he printed the pastoral and pagan drama of _Pan and the Young Shepherd_, shortened for purposes of representation and produced at the Court Theatre in March 1905, when it was followed by the _Youngest of the Angels_, dramatized from a chapter in his _Fool Errant_. In _Little Novels of Italy_ (1899), a collection of brilliant short stories, he showed again his power of literary expression together with a close knowledge of medieval Italy. The new and vivid portraits of Richard Coeur de Lion in his _Richard Yea-and-Nay_ (1900), and of Mary, queen of Scots, in _The Queen's Quair_ (1904) showed the combination of fiction with real history at its best. _The New Canterbury Tales_ (1901) was another volume of stories of English life, but he returned to Italian subjects with _The Road in Tuscany_ (1904); in _Fond Adventures, Tales of the Youth of the World_ (1905), two are Italian tales, and _The Fool Errant_ (1905) purports to be the memoirs of Francis Antony Stretley, citizen of Lucca. Later works were the novel _The Stooping Lady_ (1907), and a volume of poems, _Artemision_ (1909).

HEXAMETER, the name of the earliest and most important form of classical verse in dactylic rhythm. The word is due to each line containing six feet or measures ([Greek: metra]), the last of which must be a spondee and the penultimate a dactyl, though occasionally, for some special effect, a spondee may be allowed in the fifth foot, when the line is said to be spondaic. The four other feet may be either spondees or dactyls. All the great heroic and epic verse of the Greek and Roman poets is in this metre, of which the finest examples are to be found in Homer and in Virgil. Varied cadences and varied caesura are essential to this form of verse, otherwise the monotony is wearying to the ear. The most usual places for the caesura are at the middle of the third, or the middle of the fourth foot: the former is known as the penthemimeral and the latter as hepthemimeral caesura. There are several more or less successful examples of English poems in this metre, for example Longfellow's _Evangeline_, Kingsley's _Andromeda_ and Clough's _Bothie of Tober-na-Vuoilich_, but it does not really suit the genius of the English language. In English the lack of true spondees is severely felt, even though the English metre depends, not, as in Greek and Latin, on the distinction between long and short syllables, but on that between accented and unaccented syllables. The accent must always (or it sounds very ugly) fall on the first syllable, whatever may have been the case in Greek and Latin--Voss, Klopstock and Goethe have written hexameter poems of varying merit and the metre suits the German language distinctly better than the English. The customary form of hexameter in English verse is exemplified by Coleridge's descriptive line:--

"In the hex | ameter | rises the | fountain's | silvery | column."

Several modern poets, and in particular Robert Browning, and Lord Bowen (1835-1894) have used with effect a truncated hexameter consisting of the usual verse deprived of its last syllable. Thus Browning:--

"Well, it is I gone at | last, the | palace of | music I | reared."

It is not sufficiently observed that even the classic Greek poets introduced considerable variations into their treatment of the hexameter. These have been treated with erudition in G. Hermann's _De aetate scriptoris Argonauticorum_. The differences in the hexameters of the Latin poets were not so remarkable, but even these varied, in various epochs, their treatment of the separate feet, and the position of the caesura. The satirists in particular allowed themselves an extraordinary licence: these hexameters, from Persius, are as far removed from the rhythm of Homer, or even of Virgil, as possible, if they are to remain hexameters:--

"Mane piger stertis. 'Surge!' inquit Avaritia, 'heia Surge!' negas; instat 'Surge!' inquit 'Non queo.' 'Surge!' 'Et quid agam?' 'Rogitas? en saperdam advehe Ponto.'"

It is also to be noted that various prosodical liberties, due originally to the extreme antiquity of the hexameter, and long reformed and repressed by the culture of poets, were apt to be revived in later ages, by writers who slavishly copied the most antique examples of the art of verse.

See Wilhelm Christ, _Metrik der Griechen und Romer_, 2te Aufl. (1879).

HEXAPLA (Gr. for "sixfold"), the term for an edition of the Bible in six versions, and especially the edition of the Old Testament compiled by Origen, which placed side by side (1) Hebrew, (2) Hebrew in Greek character, (3) Aquila, (4) Symmachus, (5) Septuagint, (6) Theodotion. See BIBLE: _Old Testament, Texts and Versions_.

HEXAPODA (Gr. [Greek: hex], six, and [Greek: pous], foot), a term used in systematic zoology for that class of the ARTHROPODA, popularly known as insects. Linnaeus in his _Systema naturae_ (1735) grouped under the class Insecta all segmented animals with firm exoskeleton and jointed limbs--that is to say, the insects, centipedes, millipedes, crustaceans, spiders, scorpions and their allies. This assemblage is now generally regarded as a great division (phylum or sub-phylum) of the animal kingdom and known by K. T. E. von Siebold's (1848) name of Arthropoda. For the class of the true insects included in this phylum, Linnaeus's old term Insecta, first used in a restricted sense by M. J. Brisson (1756), is still adopted by many zoologists, while others prefer the name Hexapoda, first used systematically in its modern sense by P. A. Latreille in 1825 (_Familles naturelles du regne animal_), since it has the advantage of expressing, in a single word, an important characteristic of the group. The terms "Hexapoda" and "hexapod" had already been used by F. Willughby, J. Ray and others in the late 17th century to include the active larvae of beetles, as well as bugs, lice, fleas and other insects with undeveloped wings.

_Characters._

A true insect, or member of the class Hexapoda, may be known by the grouping of its body-segments in three distinct regions--a head, a thorax and an abdomen--each of which consists of a definite number of segments. In the terminology proposed by E. R. Lankester the arrangement is "nomomeristic" and "nomotagmic." The head of an insect carries usually four pairs of conspicuous appendages--feelers, mandibles and two pairs of maxillae, so that the presence of four primitive somites is immediately evident. The compound eyes of insects resemble so closely the similar organs in Crustaceans that there can hardly be reasonable doubt of their homology, and the primitively appendicular nature of the eyes in the latter class suggests that in the Hexapoda also they represent the appendages of an anterior (protocerebral) segment. Behind the antennal (or deutocerebral) segment an "intercalary" or tritocerebral segment has been demonstrated by W. M. Wheeler (1893) and others in various insect embryos, while in the lowest insect order--the Aptera--a pair of minute jaws--the maxillulae--in close association with the tongue are present, as has been shown by H. J. Hansen (1893) and J. W. Folsom (1900). Distinct vestiges of the maxillulae exist also in the earwigs and booklice, according to G. Enderlein and C. Borner (1904), and they are very evident in larval may-flies. The number of limb-bearing somites in the insectan head is thus seen to be seven. All of these are to be regarded as primitively post-oral, but in the course of development the mouth moves back to the mandibular segment, so that the first three somites--ocular, antennal and intercalary--lie in front of it. In Lankester's terminology, therefore, the head of an insect is "triprosthomerous." The maxillae of the hinder pair become more or less fused together to form a "lower lip" or labium, and the segment of these appendages is, in some insects, only imperfectly united with the head-capsule.