Chapter 14

For further details and illustrations of Ḥanukkah lamps seeJewish Encyc., s.v.

HANUMAN,in Hindu mythology, a monkey-god, who forms a central figure in theRamayana. He was the child of a nymph by the god of the wind. His exploits, as the ally of Rama (incarnation of Vishnu) in the latter’s recovery of his wife Sita from the clutches of the demon Ravana, include the bridging of the straits between India and Ceylon with huge boulders carried away from the Himalayas. He is the leader of a host of monkeys who aid in these supernatural deeds. Temples in his honour are frequent throughout India.

HANWAY, JONAS(1712-1786), English traveller and philanthropist, was born at Portsmouth in 1712. While still a child, his father, a victualler, died, and the family moved to London. In 1729 Jonas was apprenticed to a merchant in Lisbon. In 1743, after he had been some time in business for himself in London, he became a partner with Mr Dingley, a merchant in St Petersburg, and in this way was led to travel in Russia and Persia. Leaving St Petersburg on the 10th of September 1743, and passing south by Moscow, Tsaritsyn and Astrakhan, he embarked on the Caspian on the 22nd of November, and arrived at Astrabad on the 18th of December. Here his goods were seized by Mohammed Hassan Beg, and it was only after great privations that he reached the camp of Nadir Shah, under whose protection he recovered most (85%) of his property. His return journey was embarrassed by sickness (at Resht), by attacks from pirates, and by six weeks’ quarantine; and he only reappeared at St Petersburg on the 1st of January 1745. He again left the Russian capital on the 9th of July 1750 and travelled through Germany and Holland to England (28th of October). The rest of his life was mostly spent in London, where the narrative of his travels (published in 1753) soon made him a man of note, and where he devoted himself to philanthropy and good citizenship. In 1756 he founded the Marine Society, to keep up the supply of British seamen; in 1758 he became a governor of the Foundling, and established the Magdalen, hospital; in 1761 he procured a better system of parochial birth-registration in London; and in 1762 he was appointed a commissioner for victualling the navy (10th of July); this office he held till October 1783. He died, unmarried, on the 5th of September 1786. He was the first Londoner, it is said, to carry an umbrella, and he lived to triumph over all the hackney coachmen who tried to hoot and hustle him down. He attacked “vail-giving,” or tipping, with some temporary success; by his onslaught upon tea-drinking he became involved in controversy with Johnson and Goldsmith. His last efforts were on behalf of little chimney-sweeps. His advocacy of solitary confinement for prisoners and opposition to Jewish naturalization were more questionable instances of his activity in social matters.

Hanway left seventy-four printed works, mostly pamphlets; the only one of literary importance is theHistorical Account of British Trade over the Caspian Sea, with a Journal of Travels, &c. (London, 1753). On his life, see also Pugh,Remarkable Occurrences in the Life of Jonas Hanway(London, 1787);Gentleman’s Magazine, vol. xxxii. p. 342; vol. lvi. pt. ii. pp. 812-814, 1090, 1143-1144; vol. lxv. pt. ii. pp. 721-722, 834-835;Notes and Queries, 1st series, i. 436, ii. 25; 3rd series, vii. 311; 4th series, viii. 416.

HANWELL,an urban district in the Brentford parliamentary division of Middlesex, England, 10½ m. W. of St Paul’s cathedral, London, on the river Brent and the Great Western railway. Pop. (1891) 6139; (1901) 10,438. It ranks as an outer residential suburb of London. The Hanwell lunatic asylum of the county of London has been greatly extended since its erection 1831, and can accommodate over 2500 inmates. The extensive cemeteries of St Mary Abbots, Kensington, and St George, Hanover Square, London, are here. In the churchyard of St Mary’s church was buried Jonas Hanway (d. 1786), traveller, philanthropist, and by repute, introducer of the umbrella into England. The Roman Catholic Convalescent Home for women and children was erected in 1865. Before the Norman period the manor of Hanwell belonged to Westminster Abbey.

HAPARANDA(FinnishHaaparanta, “Aspen Shore”), a town of Sweden in the district (län) of Norbotten, at the head of the Gulf of Bothnia. Pop. (1900) 1568. It lies about 1½ m. from the mouth of the Torne river, on the frontier with Russia (Finland), opposite the town of Torneå which has belonged to Russia since 1809. The towns are divided by a marshy channel, formerly the bed of the Torne, but the main stream is now east of the Russian town. Haparanda was founded in 1812, and at first bore the name of Karljohannstad. It received its municipal constitution in 1842. Shipbuilding is prosecuted. Sea-going vessels load and unload at Salmio, 7 m. from Haparanda. Since 1859 the town has been the seat of an important meteorological station. Annual mean temperature, 32.4° Fahr.; February 10.5°; July 58.8°. Rainfall, 16.5 in. annually. Up the Torne valley (54 m.) is the hill Avasaxa, whither pilgrimages were formerly made in order to stand in the light of the sun at midnight on St John’s day (June 24).

HAPLODRILI(so called by Lankester), often called Archiannelida (Hatschek), the name provisionally given to a number of interesting lowly-organized marine worms, whose affinities are very doubtful (seeChaetopoda.)PolygordiusandProtodriluslive in sand, but while the former moves by means of the contraction of its body-wall muscles,Protodriluscan progress by the action of the bands of cilia surrounding its segments, and of the longitudinal ciliated ventral groove.Saccocirrus, which also lives in sand, and more closely resembles the Polychaeta, has throughout the greater length of its body on each segment a pair of small uniramous parapodia bearing a bunch of simple setae. No other member of the group is known to have any trace of setae or parapodia at any stage of development.

A,Polygordius neapolitanus. (From Fraipont.)

B, Transverse section ofPolygordius. (From Fraipont.)

C, Trochophore ofPolygordius. and D, later stage of the same, showing the development of the trunk. (From Hatschek.)

E, Dorsal view ofDinophilus taeniatus.

F, Male apparatus of the same (From Harmer.)

a, Anus.

ap, Apical organ.

c, Coelom.

c.o, Ciliated pit.

c.t, Cuticle.

d.v, Dorsal vessel.

e, Eye.

ep, Epidermis.

g.f, Genital funnel.

h, “Head kidney,” with second nephridium just below it.

i, Intestine.

l.m, Longitudinal muscles.

m, Mouth.

m.o, Muscular pharyngeal organ.

m.p, Male pore.

n, Nephridium.

o.m, Oblique muscles.

ov, Ovary.

p, Penis.

pr, Prototroch.

pt, Prostomial tentacle.

sp, Sperm-sac.

spd, Sperm-duct.

st, Stomach.

t, Testes.

tr, Trunk segment.

tt, Telotroch.

v.n, Ventral nerve cord.

v.v, Ventral vessel.

These three genera have the following characters in common. The body is composed of a large number of segments; the prostomium bears a pair of tentacles; the nervous system consists of a brain and longitudinal ventral nerve cords closely connected with the epidermis (without distinct ganglia), widely separated inSaccocirrus, closely approximated inProtodrilus, fused together inPolygordius; the coelom is well developed, the septa are distinct, and the dorsal and ventral longitudinal mesenteries are complete; the nephridia are simple, and open into the coelom. Polygordius differs fromProtodrilusandSaccocirrusin the absence of a distinct suboesophageal muscular pouch, and in the absence of a peculiar closed cavity in the head region, which is especially well developed inSaccocirrus, and probably represents the specialized coelom of the first segment. Moreover, inSaccocirrusthe genital organs, present in the majority of the trunk segments, have become much complicated (fig. 2). In the female there is in every fertile segment a pair of spermathecae opening at the nephridiopores. In the male there are a right and a left protrusible penis in every genital segment, into which opens the nephridium and a sperm-sac. The wide funnels of the nephridia of this region are possibly of coelomic origin.Fig. 2.—Diagram of a transverse section ofSaccocirrusshowing on the left side the organs in a genital segment of a male, and on the right side the organs in a genital segment of a female. (From Goodrich.)Dinophilusis a free-swimming form without tentacles, and with segmental bands of cilia (fig. 1). The parasiticHistriodritus(Histriobdella) feeds on the eggs of the lobster. It resemblesDinophilusin the possession of a ventral pharyngeal pouch (which bears teeth inHistriodrilusonly), the small number of segments, and absence of distinct septa, the absence of a vascular system, the presence of distinct ganglia on the ventral nerve cords, and of small nephridia which do not appear to open internally.HistriodrilusresemblesSaccocirrusin the possession of two posterior adhesive processes, and to some extent in the structure of the complex genital organs, which, however, are restricted to a single segment. InDinophilus, there is also only a single pair of genital ducts behind; and in the male there are sperm-sacs and a median penis. In some species ofDinophilusthere is pronounced sexual dimorphism (the male being small and without gut) as in the Rotifera. The resemblance ofDinophilusto the Rotifera is, however, quite superficial, and the general structure of this genus with distinct traces of segmentation, especially in the embryo, points to its close affinity, if not toPolygordiusin particular, at all events to the Annelida.ThatPolygordius,ProtodrilusandSaccocirrusare on the whole primitive forms, and related to each other, there can be little doubt, but their place amongst the Annelida is difficult to determine. The development ofPolygordiusalone is well known, having been studied by Hatschek, Fraipont and others. The larva (fig. 1, C and D) is a typical but very specialized form of trochophore, provided with a branching nephridium bearing solenocytes. The trunk develops on the lower surface of the disk-like larva, which undergoes a more or less sudden metamorphosis into the young worm (fig. 1). There appears to be little either in the development or in the structure of the Haplodrili to warrant the view held by Hatschek and Fraipont thatPolygordiusandProtodrilusare exceedingly primitive forms, ancestral to the whole group of seta-bearing Annelids (Oligochaeta, Polychaeta, Hirudinea and Echiuroidea).Whatever may be the conclusion as to the position ofDinophilusandHistriodrilus, it seems only reasonable to suppose thatPolygordiusandProtodrilus, so far from representing a stage in the phylogeny of the Annelida before setae were developed, have lost the setae, which are already in a reduced state inSaccocirrus.Authorities.—Hatschek, “Studien z. Entw. der Anneliden,”Arb. Zool. Inst. Wien, vol. i., 1878; “Protodrilus,” ibid. vol. iii. (1881); Fraipont, “Le Genre Polygordius,”Fauna u. Flora d. Golfes v. Neapel., xiv., 1887; Weldon, “Dinophilus gigas,”Quart. Journ. Micr. Sci.vol. xxvii., 1886; Harmer, “Dinophilus,”Journ. Mar. Biol.N.S. vol. i., 1889; Schimkewitsch, “Entwickl. desDinophilus,” Zeit. f. wiss. Zool.vol. lix., 1895; Korschelt, “Über Bau u. Entw. desDinophilus,”Zeit. f. wiss. Zool.vol. xxxvii., 1882; Foettinger, “Histriobdella,”Arch. Biol.vol. v., 1884; Goodrich, “On Saccocirrus,”Quart. Journ. Micr. Sci.vol. xliv., 1901.

Dinophilusis a free-swimming form without tentacles, and with segmental bands of cilia (fig. 1). The parasiticHistriodritus(Histriobdella) feeds on the eggs of the lobster. It resemblesDinophilusin the possession of a ventral pharyngeal pouch (which bears teeth inHistriodrilusonly), the small number of segments, and absence of distinct septa, the absence of a vascular system, the presence of distinct ganglia on the ventral nerve cords, and of small nephridia which do not appear to open internally.HistriodrilusresemblesSaccocirrusin the possession of two posterior adhesive processes, and to some extent in the structure of the complex genital organs, which, however, are restricted to a single segment. InDinophilus, there is also only a single pair of genital ducts behind; and in the male there are sperm-sacs and a median penis. In some species ofDinophilusthere is pronounced sexual dimorphism (the male being small and without gut) as in the Rotifera. The resemblance ofDinophilusto the Rotifera is, however, quite superficial, and the general structure of this genus with distinct traces of segmentation, especially in the embryo, points to its close affinity, if not toPolygordiusin particular, at all events to the Annelida.

ThatPolygordius,ProtodrilusandSaccocirrusare on the whole primitive forms, and related to each other, there can be little doubt, but their place amongst the Annelida is difficult to determine. The development ofPolygordiusalone is well known, having been studied by Hatschek, Fraipont and others. The larva (fig. 1, C and D) is a typical but very specialized form of trochophore, provided with a branching nephridium bearing solenocytes. The trunk develops on the lower surface of the disk-like larva, which undergoes a more or less sudden metamorphosis into the young worm (fig. 1). There appears to be little either in the development or in the structure of the Haplodrili to warrant the view held by Hatschek and Fraipont thatPolygordiusandProtodrilusare exceedingly primitive forms, ancestral to the whole group of seta-bearing Annelids (Oligochaeta, Polychaeta, Hirudinea and Echiuroidea).Whatever may be the conclusion as to the position ofDinophilusandHistriodrilus, it seems only reasonable to suppose thatPolygordiusandProtodrilus, so far from representing a stage in the phylogeny of the Annelida before setae were developed, have lost the setae, which are already in a reduced state inSaccocirrus.

Authorities.—Hatschek, “Studien z. Entw. der Anneliden,”Arb. Zool. Inst. Wien, vol. i., 1878; “Protodrilus,” ibid. vol. iii. (1881); Fraipont, “Le Genre Polygordius,”Fauna u. Flora d. Golfes v. Neapel., xiv., 1887; Weldon, “Dinophilus gigas,”Quart. Journ. Micr. Sci.vol. xxvii., 1886; Harmer, “Dinophilus,”Journ. Mar. Biol.N.S. vol. i., 1889; Schimkewitsch, “Entwickl. desDinophilus,” Zeit. f. wiss. Zool.vol. lix., 1895; Korschelt, “Über Bau u. Entw. desDinophilus,”Zeit. f. wiss. Zool.vol. xxxvii., 1882; Foettinger, “Histriobdella,”Arch. Biol.vol. v., 1884; Goodrich, “On Saccocirrus,”Quart. Journ. Micr. Sci.vol. xliv., 1901.

(E. S. G.)

HAPTARA(lit.conclusion), the Hebrew title given to the prophetic lessons with which the ancient Synagogue service concluded. In the time of Christ these prophetic lessons were already in vogue, and Christ himself read the lessons and discoursed on them in the synagogues of Galilee. In the modern synagogue these readings from the prophets are regularly included in the ritual of Sabbaths, festivals and some other occasions.

A list of the current lessons is given in theJewish Encyclopedia, vol. vi. pp. 136-137.

(I. A.)

HAPUR,a town of British India in the Meerut district of the United Provinces, 18 m. S. of Meerut. Pop. (1901) 17,796. It is said to have been founded in the 10th century, and was granted by Sindhia to his French general Perron at the end of the 18th century. Several fine groves surround the town, but the wall and ditch have fallen out of repair, and only the names of the five gates remain. Considerable trade is carried on in sugar, grain, cotton, timber, bamboos and brass utensils.

HARA-KIRI(Japanesehara, belly, andkiri, cutting), self-disembowelment, primarily the method of suicide permitted to offenders of the noble class in feudal Japan, and later the national form of honourable suicide. Hara-kiri has been often translated as “the happy dispatch” in confusion with a native euphemism for the act. More usually the Japanese themselves speak of hara-kiri by its Chinese synonym,Seppuku. Hara-kiri is not an aboriginal Japanese custom. It was a growth of medieval militarism, the act probably at first being prompted by the desire of the noble to escape the humiliation of falling into an enemy’s hands. By the end of the 14th century the custom had become a much valued privilege, being formally established as such under the Ashi-Kaga dynasty. Hara-kiri was of two kinds, obligatory and voluntary. The first is the more ancient. An official or noble, who had broken the law or been disloyal, received a message from the emperor, couched always in sympathetic and gracious tones, courteously intimating that he must die. The mikado usually sent a jewelled dagger with which the deed might be done. The suicide had so many days allotted to him by immemorial custom in which to make dignified preparations for the ceremony, which was attended by the utmost formality. In his own baronial hall or in a temple a daïs 3 or 4 in. from the ground was constructed. Upon this was laid a rug of red felt. The suicide, clothed in his ceremonial dress as an hereditary noble, and accompanied by his second or “Kaishaku,” took his place on the mat, the officials and his friends ranging themselves in a semicircle round the daïs. After a minute’s prayer the weapon was handed to him with many obeisances by the mikado’s representative, and he then made a public confession of his fault. He then stripped to the waist. Every movement in the grim ceremony was governed by precedent, and he had to tuck his wide sleeves under his knees to prevent himself falling backwards, for a Japanese noble must die falling forward. A moment later he plunged the dagger into his stomach below the waist on the left side, drew it across to the right and, turning it, gave a slight cut upward. At the same moment the Kaishaku who crouched at his friend’s side, leaping up, brought his sword down on the outstretched neck. At the conclusion of the ceremony the bloodstained dagger was taken to the mikado as a proof of the consummation of the heroic act. The performance of hara-kiri carried with it certain privileges. If it was by order of the mikado half only of a traitor’s property was forfeited to the state. If the gnawings of conscience drove the disloyal noble to voluntary suicide, his dishonour was wiped out, and his family inherited all his fortune.

Voluntary hara-kiri was the refuge of men rendered desperate by private misfortunes, or was committed from loyalty to a dead superior, or as a protest against what was deemed a false national policy. This voluntary suicide still survives, a characteristic case being that of Lieutenant Takeyoshi who in 1891 gave himself the “belly-cut” in front of the graves of his ancestors at Tōkyo as a protest against what he considered the criminal lethargy of the government in not taking precautions against possible Russian encroachments to the north of Japan. In the Russo-Japanese War, when faced by defeat at Vladivostock, the officer in command of the troops on the transport “Kinshu Maru” committed hara-kiri. Hara-kiri has not been uncommon among women, but in their case the mode is by cutting the throat. The popularity of this self-immolation is testified to by the fact that for centuries no fewer than 1500 hara-kiris are said to have taken place annually, at least half being entirely voluntary. Stories of amazing heroism are told in connexion with the performance of the act. One noble, barely out of his teens, not content with giving himself the customary cuts, slashed himself thrice horizontally and twice vertically. Then he stabbed himself in the throat until the dirk protruded on the other side with the sharp edge to the front, and with a supreme effort drove the knife forward with both hands through his neck. Obligatory hara-kiri was obsolete in the middle of the 19th century, and was actually abolished in 1868.

See A. B. Mitford,Tales of Old Japan; Basil Hall Chamberlain,Things Japanese(1898).

HARALD,the name of four kings of Norway.

Harald I.(850-933), surnamed Haarfager (of the beautiful hair), first king over Norway, succeeded on the death or his father Halfdan the Black inA.D.860 to the sovereignty of several small and somewhat scattered kingdoms, which had come into his father’s hands through conquest and inheritance and lay chiefly in south-east Norway (seeNorway). The tale goes that the scorn of the daughter of a neighbouring king induced Harald to take a vow not to cut nor comb his hair until he was sole king of Norway, and that ten years later he was justified in trimming it; whereupon he exchanged the epithet “Shockhead” for the one by which he is usually known. In 866 he made the first of a series of conquests over the many petty kingdoms which then composed Norway; and in 872, after a great victory at Hafrsfjord near Stavanger, he found himself king over the whole country. His realm was, however, threatened by dangers from without, as large numbers of his opponents had taken refuge, not only in Iceland, then recently discovered, but also in the Orkneys, Shetlands, Hebrides and Faeroes, and in Scotland itself; and from these winter quarters sallied forth to harry Norway as well as the rest of northern Europe. Their numbers were increased by malcontents from Norway, who resented Harald’s claim of rights of taxation over lands which the possessors appear to have previously held in absolute ownership. At last Harald was forced to make an expedition to the west to clear the islands and Scottish mainland of Vikings. Numbers of them fled to Iceland, which grew into an independent commonwealth, while the Scottish isles fell under Norwegian rule. The latter part of Harald’s reign was disturbed by the strife of his many sons. He gave them all the royal title and assigned lands to them which they were to govern as his representatives; but this arrangement did not put an end to the discord, which continued into the next reign. When he grew old he handed over the supreme power to his favourite son Erik “Bloody Axe,” whom he intended to be his successor. Harald died in 933, in his eighty-fourth year.

HARALD II., surnamed Graafeld, a grandson of Harald I., became, with his brothers, ruler of the western part of Norway in 961; he was murdered in Denmark in 969.

Harald III.(1015-1066), king of Norway, surnamed Haardraade, which might be translated “ruthless,” was the son of King Sigurd and half-brother of King Olaf the Saint. At the age of fifteen he was obliged to flee from Norway, having taken part in the battle of Stiklestad (1030), at which King Olaf met his death. He took refuge for a short time with Prince Yaroslav of Novgorod (a kingdom founded by Scandinavians), and thence went to Constantinople, where he took service under the empress Zoe, whose Varangian guard he led to frequent victory in Italy, Sicily and North Africa, also penetrating to Jerusalem. In the year 1042 he left Constantinople, the story says because he was refused the hand of a princess, and on his way back to his own country he married Ellisif or Elizabeth, daughter of Yaroslav of Novgorod. In Sweden he allied himself with the defeated Sven of Denmark against his nephew Magnus, now king of Norway, but soon broke faith with Sven and accepted an offer from Magnus of half his kingdom. In return for this gift Harald is said to have shared with Magnus the enormous treasure which he had amassed in the East. The death of Magnus in 1047 put an end to the growing jealousies between the two kings, and Harald turned all his attention to the task of subjugating Denmark, which he ravaged year after year; but he met with such stubborn resistance from Sven that in 1064 he gave up the attempt and made peace. Two years afterwards, possibly instigated by the banished Earl Tostig of Northumbria, he attempted the conquest of England, to the sovereignty of which his predecessor had advanced a claim as successor of Harthacnut. In September 1066 he landed in Yorkshire with a large army, reinforced from Scotland, Ireland and the Orkneys; took Scarborough by casting flaming brands into the town from the high ground above it; defeated the Northumbrian forces at Fulford; and entered York on the 24th of September. But the following day the English Harold arrived from the south, and the end of the long day’s fight at Stamford Bridge saw the rout of the Norwegian forces after the fall of their king (25th of September 1066). He was only fifty years old, but he was the first of the six kings who had ruled Norway since the death of Harald Haarfager to reach that age. As a king he was unpopular on account of his harshness and want of good faith, but his many victories in the face of great odds prove him to have been a remarkable general, of never-failing resourcefulness and indomitable courage.

Harald IV.(d. 1136), king of Norway, surnamed Gylle (probably fromGylle Krist,i.e.servant of Christ), was born in Ireland about 1103. About 1127 he went to Norway and declared he was a son of King Magnus III. (Barefoot), who had visited Ireland just before his death in 1103, and consequently a half-brother of the reigning king, Sigurd. He appears to have submitted successfully to the ordeal of fire, and the alleged relationship was acknowledged by Sigurd on condition that Harald did not claim any share in the government of the kingdom during his lifetime or that of his son Magnus. Living on friendly terms with the king, Harald kept this agreement until Sigurd’s death in 1130. Then war broke out between himself and Magnus, and after several battles the latter was captured in 1134, his eyes were put out, and he was thrown into prison. Harald now ruled the country until 1136, when he was murdered by Sigurd Slembi-Diakn, another bastard son of Magnus Barefoot. Four of Harald’s sons, Sigurd, Ingi, Eysteinn and Magnus, were subsequently kings of Norway.

HARBIN,orKharbin, town of Manchuria, on the right bank of the river Sungari. Pop. about 20,000. Till 1896 there was only a small village here, but in that year the town was founded in connexion with surveys for the Chinese Eastern railway company, at a point which subsequently became the junction of the main line of the Manchurian railway with the branch line southward to Port Arthur. Occupying such a position, Harbin became an important Russian military centre during the Russo-Japanese War. The portion of the town founded in 1896 is called Old Harbin, but the centre has shifted to New Harbin, where the chief public buildings and offices of the railway administration are situated. The river-port forms a third division of the town, industrially the most important; here are railway workshops, factories and mercantile establishments. Trade is chiefly in the hands of the Chinese.

HARBINGER,originally one who provides a shelter or lodging for an army. The word is derived from the M. E. and O. Fr.herbergere, through the Late Lat.heribergator, formed from the O. H. Ger.heri, mod. Ger.Heer, an army, andbergen, shelter or defence, cf. “harbour.” The meaning was soon enlarged to include any place where travellers could be lodged or entertained, and also by transference the person who provided lodgings, and so one who goes on before a party to secure suitable lodgings in advance. A herald sent forward to announce the coming of a king. A Knight Harbinger was an officer in the royal household till 1846. In these senses the word is now obsolete. It is used chiefly in poetry and literature for one who announces the immediate approach of something, a forerunner. This is illustrated in the “harbinger of spring,” a name given to a small plant belonging to the Umbelliferae, which has a tuberous root, and small white flowers; it is found in the central states of North America, and blossoms in March.

HARBOUR(from M. E.hereberge,here, an army; cf. Ger.Heerand -beorg, protection or shelter. Other early forms in English wereherberweandharborow, as seen in various place names, such as Market Harborough. The Frenchauberge, an inn, derived throughheberger, is thus the same word), a place of refuge or shelter. It is thus used for an asylum for criminals, and particularly for a place of shelter for ships.

Sheltered sites along exposed sea-coasts are essential for purposes of trade, and very valuable as refuges for vessels from storms. In a few places, natural shelter is found in combination with ample depth, as in the Bay of Rio de Janeiro, New York Harbour (protected by Long Island), Portsmouth Harbour and Southampton Water (sheltered by the Isle of Wight), and the land-locked creeks of Milford Haven and Kiel Harbour. At various places there are large enclosed areas which have openings into the sea; but these lagoons for the most part are very shallow except in the main channels and at their outlets. Access to them is generally obstructed by a bar as at the lagoon harbour of Venice (fig. 1), and similar harbours, like those of Poole and Wexford; and such harbours usually require works to prevent their deterioration, and to increase the depth near their outlet. Generally, however, harbours are formed where shelter is provided to a certain extent by a bay, creek or projecting headland, but requires to be rendered complete by one or more breakwaters (seeBreakwater), or where the approach to a river, a ship-canal or a seaport, needs protection. A refuge harbour is occasionally constructed where a long length of stormy coast, near the ordinary track of vessels, is entirely devoid of natural shelter. Naval harbours are required by maritime powers as stations for their fleets, and dockyards for construction and repairs, and also in some cases as places of shelter from the night attacks of torpedoes. Commercial harbours have to be provided for the formation of ports within their shelter on important trade routes, or for the protection of the approaches from the sea of ports near the sea-coast, or maritime waterways running inland, in some cases at points on the coast devoid of all natural shelter. A greater latitude in the selection of suitable sites is, indeed, possible for refuge and naval harbours than for commercial harbours; but these three classes of harbours are very similar in their general outline and the works protecting them, only differing in size and internal arrangements according to the purpose for which they have been constructed, the chief differences being due to the local conditions.

Harbours may be divided into three distinct groups, namely, lagoon harbours, jetty harbours and sea-coast harbours, protected by breakwaters, including refuge, naval and commercial harbours.

Lagoon Harbours.—A lagoon, consisting of a sort of large shallow lake separated from the sea by a narrow belt of coast, formed of deposit from a deltaic river or of sand dunes heaped up by on-shore winds along a sandy shore, possesses good natural shelter; and, owing to the large expanse which is filled and emptied at each tide, even when the tidal range is quite small, together with the dischargefrom any rivers flowing into the lagoon, one or more fairly deep outlets are maintained through the fringe of coast, which afford navigable access to the lagoon; whilst channels formed inside by the currents lead to ports on its banks. Lagoons, however, are liable to be gradually silted up, if rivers flowing into them bring down considerable quantities of alluvium, which is readily deposited in their fairly still waters; and their outlet channels are in danger of becoming shallower, by the sea in storms forming additional outlets by breaking through the narrow barrier separating them from the sea. Moreover, the approach from the sea to these channels through the fringe of coast is generally impeded by a bar, owing to the scour of the issuing current through these outlet channels becoming gradually too enfeebled, on entering the open sea, to overcome the heaping-up action of the waves along the shore, which tends to form a continuous beach across these openings. Rivers, accordingly, whose discharge is very valuable in maintaining a lagoon if their waters are free from sediment, must, if possible, be diverted from a lagoon if they bring down large amounts of silt; whilst the narrow belt of land in front of the lagoon must be protected from erosion by the waves, on its sea face, by groynes or revetments. The depth over the bar in front of an outlet can be improved by concentrating the current through the outlet by jetties on each side, and prolonging the jetties, and consequently the scour, out to the bar so as to lower it, and by supplementing the scouring action, if necessary, by dredging.Jetty Harbours.—Several small ports were formed on the sea-coast long ago at points where flat marshy ground lying below the level of high-water, and shut off from the sandy beach by dikes or sand dunes, was connected with the sea by a small creek or river. Such ports presented in their original condition a slight resemblance to lagoons on a very small scale. Several examples are to be found on the sandy shores of the English Channel and North Sea, such as Dieppe, Boulogne, Calais, Dunkirk, Nieuport and Ostend, where the influx and efflux of the water from these enclosed tide-covered areas, through a narrow opening, sufficed to maintain a shallow channel to the sea across the beach, deep enough near high-water for vessels of small draught. When the increase in draught necessitated the provision of an improved channel, the scour of the issuing current was concentrated and prolonged by erecting parallel jetties across the beach, raised solid to a little above low water of neap tides, with open timber-work above to indicate the channel and guide the vessels. Even this low obstruction, however, to the littoral drift of sand caused an advance of the low water line as the jetties were carried out, so that further extensions of the jetties had eventually to be abandoned, as occurred at Dunkirk (seeDock). Moreover, reclamation of the low-lying areas was gradually effected, thus reducing the tidal scour; and sluicing basins were excavated in part of the low ground, into which the tide flowed through the entrance channel, and the water being shut in at high tide by gates at the outlet of the basin, was released at low water, producing a rapid current through the channel as a compensation for the loss of the former natural scour. The current, however, from the sluicing basin gradually lost its velocity in passing down the channel, and besides, being most effective near the outlet of the basin, could only scour the channel down to a moderate depth below low water, on account of the increase in the volume of still water in the channel at low tide as its deepening progressed. Lastly, about 1880, improvements in suction dredgers (seeDredge and Dredging) led to the adoption of sand-pump dredging in the outer part of the channel, and across the foreshore in front to deep water; and at Dunkirk, docks were formed on the site of the sluicing basin; whilst at Calais sluicing was abandoned in favour of dredging. Ostend is the only jettyharbourin which a large sluicing basin has been recently constructed, but it can only provide for the maintenance of deep-water quays in its vicinity; and dredging is relied upon to an increasing extent, both for the maintenance and further deepening of the outer portion of the approach channel, and for maintaining the direct channel dredged to deep water across the Stroombank extending in front of Ostend (fig. 2).Fig. 2.—Ostend Harbour and Jetty Channel.Similar methods of improving the entrance channel to ports possessing an extensive backwater have been adopted on a large scale in the United States. For instance at Charleston, converging jetties, about 2¾ m. long, have been extended across the bar to concentrate the scour due to a small tidal range expanding over the enclosed backwater, 15 sq. m. in extent, and to protect the channel from littoral drift; but these jetties have caused an advance of the foreshore, and a progression seawards of the bar, necessitating dredging beyond the ends of the jetties to maintain the requisite depth.Parallel jetties, moreover, across the beach, combined with extensive sand-pump dredging, have been employed with success at some of the ports situated at the outlet of rivers, enclosed bays, or lagoons, on the sandy shores of south-east Africa, for improving the access to them across encumbering shoals, where the littoral drift is too great to allow of the projection of breakwaters from the shore to shelter an approach channel.Harbours Protected by Breakwaters.—The design for a harbour onthe sea-coast must depend on the configuration of the adjacent coast-line, the extent and direction of the exposure, the amount of sheltered area required and the depth obtainable, the prospect of the accumulation of drift or the occurrence of scour from the proposed works, and the best position for an entrance in respect of shelter and depth of approach.Fig. 3.—Genoa Harbour and Extensions.Completion of Shelter of Harbours in Bays.—In the case of a deep, fairly land-locked bay, a detached breakwater across the outlet completes the necessary shelter, leaving an entrance between each extremity and the shore, provided there is deep enough water near the shore, as effected at Plymouth harbour, and also across the wider but shallower bay forming Cherbourg harbour. A breakwater may instead be extended across the outlet from each shore, leaving a single central entrance between the ends of the breakwaters; and if one breakwater placed somewhat farther out is made to overlap an inner one, a more sheltered entrance is obtained. This arrangement has been adopted at the existing Genoa harbour within the bay (fig. 3), and for the harbour at the mouth of the Nervion (seeRiver Engineering). The adoption of a bay with deep water for a harbour does not merely reduce the shelter to be provided artificially, but it also secures a site not exposed to silting up, and where the sheltering works do not interfere with any littoral drift along the open coast. A third method of sheltering a deep bay is that adopted for forming a refuge harbour at Peterhead (fig. 4), where a single breakwater is extended out from one shore for 3250 ft. across the outlet of the bay, leaving a single entrance between its extremity and the opposite shore and enclosing an area of about 250 acres at low tide, half of which has a depth of over 5 fathoms.Fig. 4.—Peterhead Harbour of Refuge.Harbours possessing partial Natural Shelter.—The most common form of harbour is that in which one or more breakwaters supplement a certain amount of natural shelter. Sometimes, where the exposure is from one direction only, approximately parallel with the coast-line at the site, and there is more or less shelter from a projecting headland or a curve of the coast in the opposite direction, a single breakwater extending out at right angles to the shore, with a slight curve or bend inwards near its outer end, suffices to afford the necessary shelter. As examples of this form of harbour construction may be mentioned Newhaven breakwater, protecting the approach to the port from the west, and somewhat sheltered from the moderate easterly storms by Beachy Head, and Table Bay breakwater, which shelters the harbour from the north-east, and is somewhat protected on the opposite side by the wide sweep of the coast-line known as Table Bay. Generally, however, some partial embayment, or abrupt projection from the coast, is utilized as providing shelter from one quarter, which is completed by breakwaters enclosing the site, of which Dover and Colombo (fig. 5) harbours furnish typical and somewhat similar examples.Fig. 5.—Colombo Harbour.Harbours formed on quite Open Seacoasts.—Occasionally harbours have to be constructed for some special purpose where no natural shelter exists, and where on an open, sandy shore considerable littoral drift may occur. Breakwaters, carried out from the shore at some distance apart, and converging to a central entrance of suitable width, provide the requisite shelter, as for instance the harbour constructed to form a sheltered approach to the river Wear and the Sunderland docks (fig. 6). If there is little littoral drift from the most exposed quarter, the amount of sand brought in during storms, which is smaller in proportion to the depth into which the entrance is carried, can be readily removed by dredging; whilst the scour across the projecting ends of the breakwaters tends to keep the outlet free from deposit. Where there is littoral drift in both directions on an open, sandy coast, due to winds blowing alternately from opposite quarters, sand accumulates in the sheltered angles outside the harbour between each converging breakwater and the shore. This has happened at Ymuiden harbour at the entrance to the Amsterdam ship-canal on the North Sea, but there the advance of the shore appears to have reached its limit only a short distance out from the old shore-line on each side; and the only evidence of drift consists in the advance seawards of the lines of soundings alongside, and in the considerable amount of sand which enters the harbour and has to be removed by dredging. The worst results occur where the littoral drift is almost wholly in one direction, so that the projection of a solid breakwater out from the shore causes a very large accretion on the side facing the exposed quarter; whilst owing to the arrest of the travel of sand, erosion of the beach occurs beyond the second breakwater enclosing the harbour on its comparatively sheltered side. These effects have been produced at Port Said harbour at the entrance to the Suez Canal from the Mediterranean, formed by two converging breakwaters, where, owing to the prevalent north-westerly winds, the drift is from west to east, and is augmented by the alluvium issuing from the Nile. Accordingly, the shore has advanced considerably against the outer face of the western breakwater; and erosion of the beach has occurred at the shore end of the eastern breakwater, cutting it off from the land. The advance of the shore-line, however, has been much slower during recent years; and though the progress seawards of the lines of soundings close to and in front of the harbour continues, the advance is checked by the sand and silt coming from the west passing through some apertures purposely left in the western breakwater, and falling into the approach channel, from which it is readily dredged and taken away. Madras harbour, begun in 1875, consists of two breakwaters, 3000 ft. apart, carried straight out to sea at right angles to the shore for 3000 ft., and completed by two returnarms inclined slightly seawards, enclosing an area of 220 acres and leaving a central entrance, 550 ft. wide, facing the Indian Ocean in a depth of about 8 fathoms. The great drift, however, of sand along the coast from south to north soon produced an advance of the shore against the outside of the south breakwater, and erosion beyond the north breakwater; and the progression of the foreshore has extended so far seawards as to produce shoaling at the entrance. Accordingly, the closing of the entrance, and the formation of a new entrance through the outer part of the main north breakwater, facing north and sheltered by an arm starting from the angle of the northern return arm and running north parallel to the shore, round the end of which vessels would turn to enter, have been recommended, to provide a deep entrance beyond the influence of the advancing foreshore.Fig. 6.—Sunderland Harbour.Proposals have been made from time to time to evade this advance of the foreshore against a solid obstacle, by extending an open viaduct across the zone of littoral drift, and forming a closed harbour, or a sheltering breakwater against which vessels can lie, beyond the influence of accretion. This principle was carried out on a large scale at the port of call and sheltering breakwater constructed in front of the entrance to the Bruges ship-canal, at Zeebrugge on the sandy North Sea coast, where a solid breakwater, provided with a wide quay furnished with sidings and sheds, and curving round so as to overlap thoroughly the entrance to the canal and shelter a certain water-area, is approached by an open metal viaduct extending out 1007 ft. from low water into a depth of 20 ft. (fig. 7). It is hoped that by thus avoiding interference with the littoral drift close to the shore, coming mainly from the west, the accumulation of silt to the west of the harbour, and also in the harbour itself, will be prevented; and though it appears probable that some accretion will occur within the area sheltered by the breakwater, it will to some extent be disturbed by the wash of the steamers approaching and leaving the quays, and can readily be removed under shelter by dredging.Fig. 7.—Zeebrugge Harbour.Entrances to Harbours.—Though captains of vessels always wish for wide entrances to harbours as affording greater facility of safe access, it is important to keep the width as narrow as practicable, consistent with easy access, to exclude waves and swell as much as possible and secure tranquillity inside. At Madras, the width of 550 ft. proved excessive for the great exposure of the entrance, and moderate size of the harbour, which does not allow of the adequate expansion of the entering swell. Where an adequately easy and safe approach can be secured, it is advantageous to make the entrance face a somewhat sheltered quarter by the overlapping of the end of one of the breakwaters, as accomplished at Bilbao and Genoa harbours (fig. 3), and at the southern entrance to Dover harbour. Occasionally, owing to the comparative shelter afforded by a bend in the adjacent coast-line, a very wide entrance can be left between a breakwater and the shore; typical examples are furnished by the former open northern entrance to Portland harbour, now closed against torpedoes, and the wide entrances at Holyhead and Zeebrugge (fig. 7). With a large harbour and the adoption of a detached breakwater, it is possible to gain the advantage of two entrances facing different quarters, as effected at Dover and Colombo, which enables vessels to select their entrance according to the state of the wind and weather; where there is a large tidal rise they reduce the current through the entrances, and they may, under favourable conditions, create a circulation of the water in the harbour, tending to check the deposit of silt.

Jetty Harbours.—Several small ports were formed on the sea-coast long ago at points where flat marshy ground lying below the level of high-water, and shut off from the sandy beach by dikes or sand dunes, was connected with the sea by a small creek or river. Such ports presented in their original condition a slight resemblance to lagoons on a very small scale. Several examples are to be found on the sandy shores of the English Channel and North Sea, such as Dieppe, Boulogne, Calais, Dunkirk, Nieuport and Ostend, where the influx and efflux of the water from these enclosed tide-covered areas, through a narrow opening, sufficed to maintain a shallow channel to the sea across the beach, deep enough near high-water for vessels of small draught. When the increase in draught necessitated the provision of an improved channel, the scour of the issuing current was concentrated and prolonged by erecting parallel jetties across the beach, raised solid to a little above low water of neap tides, with open timber-work above to indicate the channel and guide the vessels. Even this low obstruction, however, to the littoral drift of sand caused an advance of the low water line as the jetties were carried out, so that further extensions of the jetties had eventually to be abandoned, as occurred at Dunkirk (seeDock). Moreover, reclamation of the low-lying areas was gradually effected, thus reducing the tidal scour; and sluicing basins were excavated in part of the low ground, into which the tide flowed through the entrance channel, and the water being shut in at high tide by gates at the outlet of the basin, was released at low water, producing a rapid current through the channel as a compensation for the loss of the former natural scour. The current, however, from the sluicing basin gradually lost its velocity in passing down the channel, and besides, being most effective near the outlet of the basin, could only scour the channel down to a moderate depth below low water, on account of the increase in the volume of still water in the channel at low tide as its deepening progressed. Lastly, about 1880, improvements in suction dredgers (seeDredge and Dredging) led to the adoption of sand-pump dredging in the outer part of the channel, and across the foreshore in front to deep water; and at Dunkirk, docks were formed on the site of the sluicing basin; whilst at Calais sluicing was abandoned in favour of dredging. Ostend is the only jettyharbourin which a large sluicing basin has been recently constructed, but it can only provide for the maintenance of deep-water quays in its vicinity; and dredging is relied upon to an increasing extent, both for the maintenance and further deepening of the outer portion of the approach channel, and for maintaining the direct channel dredged to deep water across the Stroombank extending in front of Ostend (fig. 2).

Similar methods of improving the entrance channel to ports possessing an extensive backwater have been adopted on a large scale in the United States. For instance at Charleston, converging jetties, about 2¾ m. long, have been extended across the bar to concentrate the scour due to a small tidal range expanding over the enclosed backwater, 15 sq. m. in extent, and to protect the channel from littoral drift; but these jetties have caused an advance of the foreshore, and a progression seawards of the bar, necessitating dredging beyond the ends of the jetties to maintain the requisite depth.

Parallel jetties, moreover, across the beach, combined with extensive sand-pump dredging, have been employed with success at some of the ports situated at the outlet of rivers, enclosed bays, or lagoons, on the sandy shores of south-east Africa, for improving the access to them across encumbering shoals, where the littoral drift is too great to allow of the projection of breakwaters from the shore to shelter an approach channel.

Harbours Protected by Breakwaters.—The design for a harbour onthe sea-coast must depend on the configuration of the adjacent coast-line, the extent and direction of the exposure, the amount of sheltered area required and the depth obtainable, the prospect of the accumulation of drift or the occurrence of scour from the proposed works, and the best position for an entrance in respect of shelter and depth of approach.

Completion of Shelter of Harbours in Bays.—In the case of a deep, fairly land-locked bay, a detached breakwater across the outlet completes the necessary shelter, leaving an entrance between each extremity and the shore, provided there is deep enough water near the shore, as effected at Plymouth harbour, and also across the wider but shallower bay forming Cherbourg harbour. A breakwater may instead be extended across the outlet from each shore, leaving a single central entrance between the ends of the breakwaters; and if one breakwater placed somewhat farther out is made to overlap an inner one, a more sheltered entrance is obtained. This arrangement has been adopted at the existing Genoa harbour within the bay (fig. 3), and for the harbour at the mouth of the Nervion (seeRiver Engineering). The adoption of a bay with deep water for a harbour does not merely reduce the shelter to be provided artificially, but it also secures a site not exposed to silting up, and where the sheltering works do not interfere with any littoral drift along the open coast. A third method of sheltering a deep bay is that adopted for forming a refuge harbour at Peterhead (fig. 4), where a single breakwater is extended out from one shore for 3250 ft. across the outlet of the bay, leaving a single entrance between its extremity and the opposite shore and enclosing an area of about 250 acres at low tide, half of which has a depth of over 5 fathoms.

Harbours possessing partial Natural Shelter.—The most common form of harbour is that in which one or more breakwaters supplement a certain amount of natural shelter. Sometimes, where the exposure is from one direction only, approximately parallel with the coast-line at the site, and there is more or less shelter from a projecting headland or a curve of the coast in the opposite direction, a single breakwater extending out at right angles to the shore, with a slight curve or bend inwards near its outer end, suffices to afford the necessary shelter. As examples of this form of harbour construction may be mentioned Newhaven breakwater, protecting the approach to the port from the west, and somewhat sheltered from the moderate easterly storms by Beachy Head, and Table Bay breakwater, which shelters the harbour from the north-east, and is somewhat protected on the opposite side by the wide sweep of the coast-line known as Table Bay. Generally, however, some partial embayment, or abrupt projection from the coast, is utilized as providing shelter from one quarter, which is completed by breakwaters enclosing the site, of which Dover and Colombo (fig. 5) harbours furnish typical and somewhat similar examples.

Harbours formed on quite Open Seacoasts.—Occasionally harbours have to be constructed for some special purpose where no natural shelter exists, and where on an open, sandy shore considerable littoral drift may occur. Breakwaters, carried out from the shore at some distance apart, and converging to a central entrance of suitable width, provide the requisite shelter, as for instance the harbour constructed to form a sheltered approach to the river Wear and the Sunderland docks (fig. 6). If there is little littoral drift from the most exposed quarter, the amount of sand brought in during storms, which is smaller in proportion to the depth into which the entrance is carried, can be readily removed by dredging; whilst the scour across the projecting ends of the breakwaters tends to keep the outlet free from deposit. Where there is littoral drift in both directions on an open, sandy coast, due to winds blowing alternately from opposite quarters, sand accumulates in the sheltered angles outside the harbour between each converging breakwater and the shore. This has happened at Ymuiden harbour at the entrance to the Amsterdam ship-canal on the North Sea, but there the advance of the shore appears to have reached its limit only a short distance out from the old shore-line on each side; and the only evidence of drift consists in the advance seawards of the lines of soundings alongside, and in the considerable amount of sand which enters the harbour and has to be removed by dredging. The worst results occur where the littoral drift is almost wholly in one direction, so that the projection of a solid breakwater out from the shore causes a very large accretion on the side facing the exposed quarter; whilst owing to the arrest of the travel of sand, erosion of the beach occurs beyond the second breakwater enclosing the harbour on its comparatively sheltered side. These effects have been produced at Port Said harbour at the entrance to the Suez Canal from the Mediterranean, formed by two converging breakwaters, where, owing to the prevalent north-westerly winds, the drift is from west to east, and is augmented by the alluvium issuing from the Nile. Accordingly, the shore has advanced considerably against the outer face of the western breakwater; and erosion of the beach has occurred at the shore end of the eastern breakwater, cutting it off from the land. The advance of the shore-line, however, has been much slower during recent years; and though the progress seawards of the lines of soundings close to and in front of the harbour continues, the advance is checked by the sand and silt coming from the west passing through some apertures purposely left in the western breakwater, and falling into the approach channel, from which it is readily dredged and taken away. Madras harbour, begun in 1875, consists of two breakwaters, 3000 ft. apart, carried straight out to sea at right angles to the shore for 3000 ft., and completed by two returnarms inclined slightly seawards, enclosing an area of 220 acres and leaving a central entrance, 550 ft. wide, facing the Indian Ocean in a depth of about 8 fathoms. The great drift, however, of sand along the coast from south to north soon produced an advance of the shore against the outside of the south breakwater, and erosion beyond the north breakwater; and the progression of the foreshore has extended so far seawards as to produce shoaling at the entrance. Accordingly, the closing of the entrance, and the formation of a new entrance through the outer part of the main north breakwater, facing north and sheltered by an arm starting from the angle of the northern return arm and running north parallel to the shore, round the end of which vessels would turn to enter, have been recommended, to provide a deep entrance beyond the influence of the advancing foreshore.

Proposals have been made from time to time to evade this advance of the foreshore against a solid obstacle, by extending an open viaduct across the zone of littoral drift, and forming a closed harbour, or a sheltering breakwater against which vessels can lie, beyond the influence of accretion. This principle was carried out on a large scale at the port of call and sheltering breakwater constructed in front of the entrance to the Bruges ship-canal, at Zeebrugge on the sandy North Sea coast, where a solid breakwater, provided with a wide quay furnished with sidings and sheds, and curving round so as to overlap thoroughly the entrance to the canal and shelter a certain water-area, is approached by an open metal viaduct extending out 1007 ft. from low water into a depth of 20 ft. (fig. 7). It is hoped that by thus avoiding interference with the littoral drift close to the shore, coming mainly from the west, the accumulation of silt to the west of the harbour, and also in the harbour itself, will be prevented; and though it appears probable that some accretion will occur within the area sheltered by the breakwater, it will to some extent be disturbed by the wash of the steamers approaching and leaving the quays, and can readily be removed under shelter by dredging.

Entrances to Harbours.—Though captains of vessels always wish for wide entrances to harbours as affording greater facility of safe access, it is important to keep the width as narrow as practicable, consistent with easy access, to exclude waves and swell as much as possible and secure tranquillity inside. At Madras, the width of 550 ft. proved excessive for the great exposure of the entrance, and moderate size of the harbour, which does not allow of the adequate expansion of the entering swell. Where an adequately easy and safe approach can be secured, it is advantageous to make the entrance face a somewhat sheltered quarter by the overlapping of the end of one of the breakwaters, as accomplished at Bilbao and Genoa harbours (fig. 3), and at the southern entrance to Dover harbour. Occasionally, owing to the comparative shelter afforded by a bend in the adjacent coast-line, a very wide entrance can be left between a breakwater and the shore; typical examples are furnished by the former open northern entrance to Portland harbour, now closed against torpedoes, and the wide entrances at Holyhead and Zeebrugge (fig. 7). With a large harbour and the adoption of a detached breakwater, it is possible to gain the advantage of two entrances facing different quarters, as effected at Dover and Colombo, which enables vessels to select their entrance according to the state of the wind and weather; where there is a large tidal rise they reduce the current through the entrances, and they may, under favourable conditions, create a circulation of the water in the harbour, tending to check the deposit of silt.

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