JOSEPH

See also:

• BARBER (from Lat. barba, beard)

BARBER

See also:

• LIGHTFOOT, JOHN (1602-1675)
• JOSEPH BARBER LIGHTFOOT (1828-1889)

LIGHTFOOT (1828-1889)  , English theologian and bishop of Durham, was born at Liverpool on the 13th of April 1828 . His father was a Liverpool accountant . He was educated at King Edward's school, Birmingham, under James Prince Lee, afterwards bishop of Manchester, and had as contemporaries B . F . Westcott and E . W . Benson . In 1847 Lightfoot went up to Trinity College, Cambridge, and there read for his degree with Westcott . He graduated senior classic and 3oth wrangler, and was elected a fellow of his college . From 1854 to 1859 he edited the Journal of Classical and Sacred Philology . In 1857 he became tutor and his fame as a scholar grew rapidly . He was made Hulsean professor in 1861, and shortly afterwards chaplain to the Prince Consort and honorary chaplain in ordinary to the queen .

In 1866 he was

Whitehall preacher, and in 1871 he became canon of St Paul's . His sermons were not remarkable for eloquence, but a certain solidity and balance of judgment, an absence of partisanship, a sobriety of expression combined with clearness and force of diction, attracted hearers and inspired them with confidence . As was written of him in The Times after his death, " his personal character carried immense weight, but his great position depended still more on the universally recognized fact that his belief in Christian truth and his defence of it were supported by learning as solid and comprehensive as could be found anywhere in Europe, and by a temper not only of the utmost candour but of the highest scientific capacity . The days in which his university influence was asserted were a time of much shaking of old beliefs . The disintegrating speculations of an influential school of criticism in Germany were making their way among English men of culture just about the time, as is usually the case, when the tide was turning against them in their own country . The peculiar service which was rendered at this juncture by the ` Cambridge School' was that, instead of opposing a mere dogmatic opposition to the Tubingen critics, they met them frankly on their own ground; and instead of arguing that their conclusions ought not to be and could not be true, they simply proved that their facts and their premisses were wrong . It was a characteristic of equal importance that Dr Lightfoot, like Dr Westcott, never discussed these subjects in the mere spirit of controversy . It was always patent that what he was chiefly concerned with was the substance and the life of Christian truth, and that his whole energies were employed in this inquiry because his whole heart was engaged in the truths and facts which were at stake . He was not diverted by controversy to side-issues; and his labour was devoted to the positive elucidation of the sacred documents in which the Christian truth is enshrined." In 1872 the anonymous publication of Supernatural Religion created considerable sensation . In a series of masterly papers in the Contemporary Review, between December 1874 and May 1877, Lightfoot successfully undertook the defence of the New Testament canon . The articles were published in collected form in 1889 . About the same time he was engaged in contributions to W .

Smith's Dictionary of Christian Biography and Dictionary of the Bible, and he also joined the committee for revising the translation of the New Testament . In 1875 he became Lady Margaret professor of divinity in succession to William Selwyn . He had previously written his commentaries on the epistles to the Galatians (1865), Philippians (1868) and Colossians (1875), the notes to which were distinguished by sound judgment and enriched from his large store of patristic and classical learning . These commentaries may be described as to a certain extent a new departure in New Testament exegesis . Before Lightfoot's time commentaries, especially on the epistles, had not infrequently consisted either of short homilies on particular portions of the text, or of endeavours to enforce foregone conclusions, or of attempts to decide with infinite industry and ingenuity between the interpretations of former commentators . Lightfoot, on the contrary, endeavoured to make his author interpret himself, and by considering the general drift of his argument to discover his meaning where it appeared doubtful . Thus he was able often to recover the meaning of a passage which had long been buried under a heap of contradictory glosses, and he founded a school in which sobriety and common sense were added to the industry and ingenuity of former commentators . In 1879 Lightfoot was consecrated bishop of Durham in succession to C . Baring . His moderation, good sense, wisdom, temper, firmness and erudition made him as successful in this position as he had been when professor of theology, and he speedily surrounded himself with a band of scholarly young men . He endeavoured to combine his habits of theological study with the practical work of administration . He exercised a large liberality and did much to further the work of temperance and purity organizations .

He continued to work at his

editions of the Apostolic Fathers, and in 1885 published an edition of the Epistles of Ignatius and Polycarp,627 collecting also a large store of valuable materials for a second edition of Clement of Rome, which was published after his death (1st ed., 1869) . His defence of the authenticity of the Epistles of Ignatius is one of the most important contributions to that very difficult controversy . His unremitting labours impaired his health and shortened his splendid career at Durham . He was never married . He died at Bournemouth on the 21st of December 1889, and was succeeded in the episcopate by Westcott, his schoolfellow and lifelong friend . Four volumes of his Sermons were published in 189o . LIGHTHOUSE, a form of building erected to carry a light for the purpose of warning or guidance, especially at sea . I . EARLY HISTORY.—The earliest lighthouses, of which records exist, were the towers built by the Libyans and Cushites in Lower Egypt, beacon fires being maintained in some of them by the priests . Lesches, a Greek poet (c.66o B.C.) mentions a lighthouse at Sigeum (now Cape Incihisari) in the Troad . This appears to have been the first light regularly maintained for the guidance of mariners . The famous Pharos 1 of Alexandria, built by Sostratus of Cnidus in the reign of Ptolemy II .

(283–247 B.C.) was regarded as one of the wonders of the

world . The tower, which took its name from that of the small island on which it was built, is said to have been 600 ft. in height, but the evidence in support of this statement is doubtful . It was destroyed by an earthquake in the 13th century, but remains are said to have been visible as late as 1350 . The name Pharos became the general term for all lighthouses, and the term " pharology " has been used for the science of lighthouse construction . The tower at Ostia was built by the emperor Claudius (A.D . 50) . Other famous Roman lighthouses were those at Ravenna, Pozzuoli and Messina . The ancient Pharos at Dover and that at Boulogne, later known as la Tour d'Ordre, were built by the Romans and were probably the earliest lighthouses erected in western Europe . Both are now demolished . The light of Cordouan, on a rock in the sea at the mouth of the Gironde, is the earliest example now existing of a wave-swept tower . Earlier towers on the same rock are attributed the first to Louis le Debonnaire (c . A.D .

805) and the second to Edward the

Black Prince . The existing structure was begun in 1584 during the reign of Henri II. of France and completed in 1611 . The upper part of the beautiful Renaissance building was removed towards the end of the 18th century and replaced by a loftier cylindrical structure rising to a height of 207 ft. above the rock and with the focal plane of the light 196 ft. above high water (fig . I) . Until the 18th century the light exhibited from the tower was from an oak log fire, and subsequently a coal fire was in use for many years . The ancient tower at Corunna, known as the Pillar of Hercules, is supposed to have been a Roman Pharos . The Torre del Capo at Genoa originally stood on the promontory of San Berrique . It was built in 1139 and first used as a lighthouse in 1326 . It was rebuilt on its present site in 1643 . This beautiful tower rises 236 ft. above the cliff, the light being elevated 384 ft. above sea-level . A lens light was first installed in 1841 . The Pharos of Meloria was constructed by the Pisans in 1154 and was several times rebuilt until finally destroyed in 1290 .

On the

abandonment of Meloria by the Pisans, they erected the still existing tower at Leghorn in 1304 . In the 17th and 18th centuries numerous towers, on which were erected braziers or grates containing wood or coal fires, were established in various positions on the coasts of Europe . Among such stations in the United Kingdom were Tynemouth (c . 16o8), the Isle of May (1636),.St Agnes (168o), St Bees (1718) and the Lizard (1751) . The oldest lighthouse in the United States is believed to be the Boston light situated on Little Brewster Island on the south side of the main entrance to Boston Harbour, Mass . It was established in 1716, the present structure dating from 1859 . During the American War of Independence the lighthouse suffered many vicissitudes and was successively destroyed and rebuilt three times by the American or British A full account is given in Hermann Thiersch, Pharos Antike, Islam and Occident (1909) . See also MINARET . forces . At the third rebuilding in 1783 a stone tower 68 ft. in height was erected, the illuminant consisting of four oil lamps . Other early lighthouse structures on the New England coast were those at Beaver Tail, near the entrance to Newport Harbour (1740), and the Brant at the entrance to Nantucket Harbour (1754) . A watch-house and beacon appear to have been erected on Beacon or Lighthouse Island as well as on Point Allerton Hill near Boston, prior to 1673, but these structures would seem to have been in the nature of look-out stations in time of war rather than lighthouses for the guidance of mariners .

2 . LIGHTHOUSE STRUCTURES.—The structures of lighthouses may be divided into two classes, (a) those on rocks, shoals or in other situations exposed to the force of the sea, and (b) the more numerous class of

land structures . Wave-swept Towers.—In determining the design of a lighthouse tower to be erected in a wave-swept position consideration must be given to the physical features of the site and its surroundings . Towers of this description are classified as follows: (i) Masonry and concrete structures; (2) Openwork steel and iron-framed erections on pile or other foundations; (3) Cast iron plated towers; (4) Structures erected on cylinder foundations . (I) Masonry Towers.—Masonry or concrete towers are generally preferred for erection on wave-swept rocks affording good foundation, and have also been constructed in other situations where adequate foundations have been made by sinking caissons into a soft sea bed . Smeaton's tower on the Eddystone Rock is the model upon which most later designs of masonry towers have been based, although many improvements in detail have since been made . In situations of great exposure the following requirements in design should be observed: (a) The centre of gravity of the tower structure should be as low as possible . (b) The mass of the structure superimposed at any horizontal section must be sufficient to prevent its displacement by the combined forces of wind and waves without dependence on the adhesion at horizontal joint faces or on the dovetailing of stones introduced as an additional safeguard . (c) The structure should be circular in plan throughout, this form affording the least resistance to wave stroke and wind pressure in any direction.(d) The lower portion of the tower exposed to the direct horizontal stroke of the waves should, for preference, be constructed with vertical face . The upper portion to be either straight with uniform batter or continuously curved in the vertical plane . External projections from the face of the tower, except in the case of a gallery under the lantern, should be avoided, the surface throughout being smooth . (e) The height from sea-level to the top of the tower should be sufficient to avoid the obscuration of the light by broken water or dense spray driving over the lantern .

(f) The foundation of the tower should be carried well into the solid rock . (g) The materials of which the tower is built should be of high

density and of resistant nature . (h) The stones used in the construction of the tower, at any rate those on the outer face, should be dovetailed or joggled one to the other in order to prevent their being dislodged by the sea during the process of construction and as an additional safe-guard of stability . Of late years, cement concrete has been used to a considerable extent for maritime structures, including lighthouses, either alone or faced with masonry . (2) Openwork Structures.—Many examples of openwork steel and iron lighthouses exist . Some typical examples are described hereafter . This form of design is suitable for situations where the tower has to be carried on a foundation of iron or steel piles driven or screwed into an insecure or sandy bottom, such as on shoals, coral reefs and sand banks or in places where other materials of construction are exceptionally costly and where facility of erection is a desideratum . (3) Cast iron Towers.—Cast iron plated towers have been erected in many situations where the cost of stone or scarcity of labour would have made the erection of a masonry tower excessively expensive . (4) Caisson Foundations.—Cylinder or caisson foundations have been used for lighthouse towers in numerous cases where such structures have been erected on sand banks or shoals . A remarkable instance is the Rothersand Tower . Two attempts have been made to sink a caisson in the outer Diamond Shoal off Cape Hatteras on the Atlantic coast of the United States, but these have proved futile . The following are brief descriptions of the more important wave-swept towers in various parts of the world .

Eddystone (Winstanley's Tower).—The Eddystone rocks, which

lie about 14 M. off Plymouth, are fully exposed to south-west seas . The reef is submerged at high water of spring tides . Four towers have been constructed on the reef . The first lighthouse (fig . 2 was polygonal in plan and highly ornamented with galleries and projections which offered considerable resistance to the sea stroke . The work was begun by Henry Winstanley, a gentleman of Essex, in 1695 . In 1698 it was finished to a height of 8o ft. to the wind vane and the light exhibited, but in the following year, in con-sequence of damage by storms, the tower was increased in diameter from 16 ft. to 24 ft. by the addition of an outer ring of masonry and made solid to a height of 20 ft. above the rock, the tower being raised to nearly 120 ft . The work was completed in the year 1700 . The lower part of the structure appears to have been of stone, the upper part and lantern of timber . During the great storm of the loth of November 1703 the tower was swept away, those in it at the time, including the builder, being drowned . Eddystone (Rudyerd's Tower, fig . 3).—This structure was begun in 1706 and completed in 1709 .

It was a

frustum of a cone 22 ft . 8 in. in diameter at the base and 14 ft . 3 in. at the top . The tower was 92 ft. in height to the top of the lantern . The work consisted principally of oak timbers securely bolted and cramped together, the lower part being filled in solid with stone to add weight to the structure . The simplicity of the design and the absence of projections from the outer face rendered the tower very suitable to withstand the onslaught of the waves . The lighthouse was destroyed by fire in 1755 . Eddystone (Smeaton's Tower, fig . 4).—This famous work, which consisted entirely of stone, was begun in 1756, the light being first exhibited in 1759 . John Smeaton was the first engineer to use dovetailed joints for the stones in a lighthouse structure . 'The stones, which averaged i ton in weight, were fastened to each other by means of dovetailed vertical joint faces, oak key wedges, and by oak tree-nails wedged top and bottom, extending vertically from every course into the stones beneath it . During the 19th century the tower was strengthened on two occasions by the addition of heavy wrought iron ties, and the overhanging cornice was reduced in diameter to prevent the waves from lifting the stones from their beds .

In 1877, owing partly to the undermining of the rock on which the tower was built and the insufficient height of the structure, the

Corporation of Trinity House determined on the erection of a explosive gun-cotton fog signal has been erected, the bells being removed . At a lower level in the tower are installed 2 2I-in. parabolic silvered reflectors with 2-wick burners, throwing a fixed light of 8000 candle-power over a danger known as the Hand Deeps . The work of pre- paring the foundation was begun on the 17th of July 1878, the foundation stone Foe°1 p,a,o being laid by the late duke of Edinburgh A -on the 19th of August 1879 . The last stone was laid on the 1st of June 1881, i and the light was exhibited for the first time on the 18th of May 1882 . The upper portion of Smeaton's tower, which was removed on completion of the new light-house, was re-erected on Plymouth Hoe, where it replaced the old Trinity House sea mark . One of the principal features in the design of the new Eddystone lighthouse tower is the solid vertical base . This construction was much criticized at the time, but experience has proved that heavy seas striking the massive cylindrical structure are immediately broken up and rush round to the opposite side, spray alone ascending to the height of the lantern gallery . On the other hand, the waves striking the old tower at its foundation ran up the surface, which presented a curved face to the waves, and, unimpeded by any projection until arriving at the lantern gallery, were partially broken up by the cornice and w. then spent themselves in heavy spray _- over the lantern . The shock to which the cornice of the gallery was exposed was so great that stones were sometimes lifted from their beds . The new Eddy- stone tower presents another point of dissimilarity from Smeaton's structure, that the stones forming the floors consist of single corbels built into the wall and constituting solid portions thereof . In Smeaton's tower the floors consisted of stone arches, the thrust being taken by the walls of the tower itself, which were strengthened for the lRudyerd ,706 Smeaton 2756 'o I o ',o ao 3o w so 6o 70 8o sp ,4o Feet in new lighthouse in place of Smeaton's tower Eddystone, New Lighthouse (J . N .

Douglass).—The site selected for the new tower is 120 ft . S.S.E. from Smeaton's lighthouse, where a suitable foundation was found, although a considerable section of the lower courses had to be laid below the level of low water . The vertical base is 44 ft. in diameter and 22 ft. in height . The tower (figs . 5 and 6) is a concave elliptic frustum, and is solid, with the exception of a fresh-water tank, to a height of 25 ft . 6 in. above high-water level . The walls above this level vary in thickness from 8 ft . 6 in. to 2 ft . 3 in. under the gallery, All the stones are Lighthouses on the Eddystone . dovetailed, both horizontally and vertically, on all joint faces, the stones of the foundation course being secured to the rock by Muntz metal bolts . The tower contains 62,133 cub. ft. of granite, weighing 4668 tons . The height of the structure from low water ordinary spring tides to the mean focal plane is 149 ft. and it stands 133 ft. above high water .

The lantern is a cylindrical helically framed structure with domed roof . The astragals are of gunmetal and the

pedestal of cast iron . The optical apparatus consists of two super-posed tiers of refracting lens panels, 12 in each tier of 920 mm. focal distance . The lenses subtend an angle of 92° vertically . The 12 lens panels are arranged in groups of two, thus producing a group flashing light showing 2 flashes of 11 seconds' duration every half minute, the apparatus revolving once in 3 minutes . The burners originally fitted in the apparatus were of 6-wick pattern, but these were replaced in 1904 by incandescent oil vapour burners . The intensity of the combined beam of light from the two apparatus is 292,000 candles . At the time of the completion of the lighthouse two bells, weighing 2 tons each and struck by mechanical power, were installed for fog-signalling purposes . Since that date an purpose by building in chains in the form of hoops (fig . 7) . The system of constructing corbelled stone floors was first adopted by R . Stevenson in the Bell Rock lighthouse (fig .

8) . Bell Rock Lighthouse (fig . 9).—The Bell Rock, which lies 12 m. off the coast of

Forfarshire, is exposed to a considerable extent at low water . The tower is submerged to a depth of about 16 ft. at high water of spring tides . The rock is of hard sandstone . The lighthouse was constructed by Robert Stevenson and is loo ft. in height, the solid portion being carried to a height of 21 ft. above high water . The work of construction was begun in 1807, and finished in 181o, the light being first exhibited in 1811 . The total weight of the tower is 2076 tons . A new lantern and dioptric apparatus were erected on the tower in 1902 . The focal plane of the light is elevated 93 ft. above high water . Skerryvore Lighthouse (fig. lo).—The Skerryvore Rocks, 12 M. off the island of Tyree in Argyllshire, are wholly open to the Atlantic . The work, designed by Alan Stevenson, was begun in 1838 and finished in 1844 .

The tower, the

pro-file of which is a hyperbolic curve, is 138 ft. high to the lantern base, 42 ft . diameter at the base, and 16 ft. at the top . Its weight is 4308 tons . The structure contains 9 rooms in addition to the lantern chamber . It is solid to a height of 26 ft. above the base . Heaux de Brehal Lighthouse.—The reef on which this tower is constructed lies off the coast of Brittany, and is submerged at high tide . The work was carried out in 1836-1839 . The tower is circular in plan with a gallery at a height of about 70 ft. above the base, The tower is 156 ft. in height from base to lantern floor . Haut Banc du Nord Lighthouse.—This tower is placed on a reef at the north-west extremity of the Ile de Re, and was constructed in 1849-1853 . It is 86 ft. in height to the lantern floor . Bishop Rock Lighthouse.—The lighthouse on the Bishop Rock, which is the westernmost landfall rock of the Scilly Islands, occupies perhaps a more exposed situation than any other in the world Lighthouse . The first lighthouse erected there was begun in 1847 under the direction of N .

Douglass . The tower consisted of a cast and wrought iron openwork structure having the columns deeply sunk into the rock . On the 5th of

February 185o, when the tower was ready for the erection of the lantern and illuminating apparatus, a heavy storm swept away the whole of the structure . This tower was de-signed for an elevation of 94 ft. to the focal plane . In 1851 the erection of a granite tower, from the designs of James Walker, was begun; the light was first exhibited in 1858 . The tower (fig . 11) had an elevation to the focal plane of Ito ft., the lower 14 courses being arranged in steps, or offsets, to break up the force of the waves . This structure also proved insufficient to withstand the very heavy seas to which it was exposed . Soon after its completion the 5-cwt. fog bell, fixed to the lantern gallery loo ft. above high-water mark, was washed away, together with the flagstaff and ladder . The tower vibrated considerably during storms, and it was found that some of the external blocks of granite had been split by the excessive stress to which they had been exposed . In 1874 the tower was strengthened by bolting continuous iron ties to the internal surfaces of the walls . In 1881, when further signs of damage appeared, it was determined to remove the upper storey or service room of the lighthouse, and to case the structure from its base upwards with granite blocks securely dovetailed to each other and to the existing work .

At the same time it was considered advisable to increase the elevation of the light, and place the mean focal plane of the new apparatus at an elevation of 146 ft. above high-water mark . The work was begun in 1883, and the new apparatus was first illuminated on the 25th of

October 1887 . During the operation of heightening the tower it was necessary to install a temporary light, consisting of a cylindrical lightship lantern with catoptric apparatus; this was raised from time to time in advance of the structure as the work proceeded . The additional masonry built into the tower amounts approximately to 3220 tons . Profiting by the experience gained after the construction of the new Eddystone tower, Sir J . N . Douglass decided to build the lower portion of the improved Bishop Rock tower in the form of a cylinder, but with considerably increased elevation (figs . 12 and 13) . The cylindrical base is 40 ft. in diameter, and rises to 25 ft. above high-water mark . The lantern is cylindrical and helically framed, 14 ft. in diameter, the glazing being 15 ft. in height . The optical apparatus consists of two superposed tiers of lenses of 1330 mm. focal distance, the lenses subtending a horizontal angle of 36° and a vertical angle of 8o° . The apparatus consists of 5 groups of lenses each group producing a double flashing light of one minute period, the whole apparatus revolving once in five minutes .

The maximum aggregate candle-power of the flash is 622,000 candles . A gun-cotton explosive fog signal is attached to the lantern . The cost of the various lighthouses on the Bishop Rock has been as follows: I . Cast iron lighthouse . . . . £12,500 0 0 2 . Granite lighthouse . 34,559 18 9 3 . Improved granite lighthouse . . 64,889 0 0 The Smalls Lighthouse.—A lighthouse has existed on the Smalls rock, 181 m. off

Milford Haven, since 1776, when an oak pile structure was erected by Henry Whiteside . The existing structure, after the model of the second lighthouse on the Bishop Rock, was erected in1856–1861 by the Trinity House and is 114 ft. in height from the foundation to the lantern floor . A new optical apparatus was in stalled in 1907 .

Minot's Ledge Lighthouse.—The tower, which is 89 ft. in height, is built of granite upon a reef off Boston Harbor, Mass., and occupied five years in construction, being completed in 186o at a cost of £62,500 . The rock just bares at low water . The stones are dovetailed vertically but not on their horizontal beds in the case of the lower 40 ft. or solid portion of the tower, bonding bolts being substituted for the horizontal dovetailed joints used in the case of the Wolf and other English towers . The shape of the tower is a conical frustum . Wolf Rock Lighthouse.—This much exposed rock lies midway between the Scilly Isles and the Lizard Point, and is submerged to the depth of about 6 ft. at high water . The tower was erected in 1862–1869 (fig . 14) . It is 116 ft . 6 in. high, 41 ft . 8 in. diameter at the base, decreasing to 17 ft. at the top . The walls are 7 ft . 91 in. thick, decreasing to 2 ft .

3 in . The

shaft is a concave elliptic frustum, and contains 3296 tons . The lower part of the tower has projecting scarcements in order to break up the sea . Dhu Heartach Rock Lighthouse.—The Dhu Heartach Rock, 35 ft. above high water, is 14 M. from the island of Mull, which is the nearest shore . The maxi-mum diameter of the tower (fig . 15), which is of parabolic outline, is 36 ft., decreasing to 16 ft.; the shaft is solid for 32 ft. above the rock; the masonry weighs 3115 tons, of which 1810 are contained in the solid part . This tower occupied six years in erection, and was completed in 1872 . Great Basses Lighthouse, Ceylon.—The Great Basses lighthouse lies 6 m. from the nearest land . The cylindrical base is 32 ft. in diameter, above which is a tower 67 ft . 5 in. high and 2 ft. in diameter . The walls vary in thickness from 5 ft. to 2 ft . The tower, including the base, contains about 2768 tons .

The work was finished in three years, 1870–1873 . Spectacle Reef Lighthouse,

Lake Huron.—This is a structure similar to that on Minot's ledge, standing on a limestone reef at the northern end of the lake . The tower (fig . 16) was constructed with a view to withstanding the effects of ice massing in solid fields thousands of acres in extent and travelling at considerable velocity . The tower is in shape the frustum of a cone, 32 ft. in diameter at the base and 93 ft. in height to the coping of the gallery . The focal plane is at a level of 97 ft. above the base . The lower 34 ft. of the tower is solid . The work was completed in 1874, having occupied four years . The cost amounted to approximately £78,000 . Chicken Rock Lighthouse.—The Chicken Rock lies I m. off the Calf of Man . The curve of the tower, which is 123 ft . 4 in. high, is hyperbolic, the diameter varying from 42 ft. to 16 ft .

The tower is sub-merged 5 ft. at high-water springs . The solid part is 32 ft . 6 in. in height, weighing 2050 tons, the whole weight of the tower being 3557 tons . The walls decrease from 9 ft . 3 in. to 2 ft . 3 in. in thickness . The work was begun in 1869 and completed in 1874 . Ar'men Lighthouse.—The masonry tower, erected by the

French Lighthouse Service, on the Ar'men Rock off the western extremity of the Ile de Sein, Finistere, occupied fifteen years in construction (1867–1881) . The rock is of small area, barely uncovered at low water, and it was therefore found impossible to construct a tower having a base diameter greater than 24 ft . The focal plane of the light is 94 ft. above high water (fig . 17) . St George's Reef Lighthouse, California.—This structure consists of a square pyramidal stone tower rising from the easterly end of an oval masonry pier, built on a rock to a height of 6o ft. above the water .

The focal plane is at an elevation of 146 ft. above high water . The site is an exceedingly dangerous one, and,the work, which was completed in 1891, cost approximately £144,000 . Rattray

Head Lighthouse.—This lighthouse was constructed between the years 1892 and 1895 by the Northern Lighthouse Commissioners upon the Ron Rock, lying about one-fifth of a mile off Rattray Head, Aberdeenshire . The focal plane is 91 ft. above high water, the building being approximately 113 ft. in height . In the tower there is a fog-horn worked by compressed air . Fastnet Lighthouse.—In the year 1895 it was reported to the Irish Lights Commissioners that the then existing lighthouse on the Fast-net Rock off the south-west coast of Ireland, which was completed in 1854 and consisted of a circular cast iron tower 86 ft. in height on the summit of the rock, was considerably undermined . It was subsequently determined to proceed with the erection of a granite structure of increased height and founded upon a sound ledge of rock on one side of the higher, but now considerably undermined . ew . Alan Stevenson 1838 James Walker rasa :, t0 52 to 00 00 40 50 60 70 80 90 too Feet }Sir J.N.Dongiasa ra87 R.Stevenson 1806 portion of the reef . This lighthouse tower has its foundation laid near high-water level . The focal plane is at a level of 158 ft. above high-water mark . The cost of the structure, which was commenced in 1899 and completed in 1904, was £79,000 .

Beachy Head Lighthouse.—A lighthouse has been erected upon the

foreshore at the foot of Beachy Head, near Eastbourne, to replace the old structure on the cliff having an elevation of 284 ft. above high-water mark . Experience proved that the light of the latter was frequently obscured by banks of mist or fog, while at the lower level the transparency of the atmosphere was considerably less impaired . The Trinity House therefore decided in the year 1899 to proceed with the construction of a granite tower upon the foreshore at a distance of some 57o ft. from the base of the cliff (fig . 18) . The foreshore at this point consists of chalk, and the selected site just bares at low water ordinary spring tides . The foundation course was laid at a depth of lo ft. below the surface, the area being excavated within a coffer-dam . The tower, which is 47 ft. in diameter at the base, has an elevation to the focal plane above high water of 103 ft., or a total height from foundation course to gallery coping of 123 ft . 6 in . The lower or solid portion of the tower has its face stones constructed in vertical offsets or steps in a similar manner to that adopted at the Wolf Rock and elsewhere . The tower is constructed with a facing of granite, all the stones being dovetailed in the usual manner . The hearting of the base is largely composed of concrete . The work was completed in 1902 and cost £56,000 .

Maplin Lighthouse.—The

screw pile lighthouse erected on the Maplin Sand in the estuary of the river Thames in 1838 is the earliest of its kind and served as a model for numerous similar structures in various parts of the world . The piles are nine in number, 5 in. diameter of solid wrought iron with screws 4 ft. diameter (fig . 19) . Fowey Rocks Lighthouse, Florida.—This iron structure, which was begun in 1875 and completed in 1878, stands on the extreme northern point of the Florida reefs . The height of the tower, which is founded on wrought iron piles driven To ft. into the coral rock, is Ito ft. from high water to focal plane . The iron openwork pyramidal structure encloses a plated iron dwelling for the accommodation of the keepers . The cost of construction amounted to £32,600 Alligator Reef Lighthouse, Florida.—T his tower is one of the finest iron sea-swept lighthouse structures in the world . It consists of a pyramidal iron framework 135 ft . 6 in. in height, standing on the Florida Reef in 5 ft. of water . The cost of the structure, which is similar to the Fowey Rocks tower, was £37,000 . American Shoal Lighthouse, Florida.—T his tower (fig . 2o) is typical of the openwork pile structures on the Florida reefs, and was completed in 1880 .

The focal plane of the light is at an elevation of I09 ft. above high water . Wolf

Trap Lighthouse.—This building was erected during the years 1893 and 1894 on Wolf Trap Spit in Chesapeake Bay, near the site of the old openwork structure which was swept away by ice early in 1893 . The new tower is formed upon a cast iron caisson 30 ft. in diameter sunk t8 ft. into the sandy bottom . The depth of water on the shoal is 16 ft. at low water . The caisson was filled with concrete, and is surmounted by a brick superstructure 52 ft. in height from low water to the focal plane of the light . A somewhat similar structure was erected in 1885–1887 on the Fourteen Foot Bank in Delaware Bay, at a cost of £24,700 . The foundation in this case was, however, shifting sand, and the caisson was carried to a greater depth . Rothersand Lighthouse.—This lighthouse, off the entrance to the river Weser (Germany), is a structure of great interest on account of the difficulties met with in its construction . The tower had to he founded on a bottom of shifting sand 20 ft. below low water and in a very exposed situation . Work was begun in May 1881, when attempts were made to sink an iron caisson under pneumatic pressure . Owing to the enormous scour removing the sand from one side of the caisson it tilted to an alarming angle, but eventually it was sunk to a level of 70 ft. below low-water mark . In October of the same year the whole structure collapsed .

Another

attempt, made in May 1883, to sink a caisson of bi-convex shape in plan 47 ft. long, 37 ft. wide and 62 ft. in height, met with success, and after many difficulties the structure was sunk to a depth of 73 ft. below low water, the sides being raised by the addition of iron plating as the caisson sank . The sand was removed from the interior by suction . Around the caisson foundation were placed 74,000 cub. yds. of mattress work and stones, the interior being filled with concrete . Towards the end of 1885 the lighthouse was completed, at a total cost, including the first attempt, of over £65,000 . The tower is an iron structure in the shape of a concave elliptic frustum, its base being founded upon the caisson foundation at about half-tide level (fig . 21) . The light is electric, the current being supplied by cable from the shore . The focal plane is 78 ft. above high water or 109 ft. from the sand level . The total height from the foundation of the caisson to the top of the vane iS 185 ft . Other famous wave-swept towers are those at Haulbowline Rock (Carlingford Lough, Ireland, 1823) ; Horsburgh (Singapore, 1851) ; Bayes d'Olonne (Bay of Biscay, 1861) ; Hanois (Alderney, 1862) ; Daedalus Reef, iron tower (Red Sea, 1863) ; Alguada Reef (Bay of Bengal, 1865) ; Longships (Land's End, 1872) ; the Prongs (Bombay, 1874) ; Little Basses (Ceylon, 1878) ; the Graves (Boston, U.S.A., M+ I: 4 4 I" III y%id -' ~io`M "Il~lf~I I _ JAI i "1A% ,\~-.~Ei ',rye \, y/ aY~ III a . III ~~~ . I I~ I `IiL yin r an rs II11 Y' 4 14 % 11 i III ,t t gy//b7y% IH u .

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