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LIGHTFOOT, JOSEPH BARBER (1828-1889)
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See also:LIGHTFOOT, See also:JOSEPH See also:BARBER (1828-1889) , See also:English theologian and See also:bishop of See also:Durham, was See also:born at See also:Liverpool on the 13th of See also:April 1828. His See also:father was a Liverpool accountant. He was educated at See also: In 1866 he was See also:Whitehall preacher, and in 1871 he became See also:canon of St See also:Paul's. His sermons were not remarkable for eloquence, but a certain solidity and See also:balance of See also:judgment, an See also: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 See also:death, " his See also:personal See also:character carried immense See also:weight, but his See also:great position depended still more on the universally recognized fact that his belief in See also:Christian truth and his See also:defence of it were supported by learning as solid and comprehensive as could be found anywhere in See also:Europe, and by a See also:temper not only of the utmost candour but of the highest scientific capacity. The days in which his university See also:influence was asserted were a See also:time of much shaking of old beliefs. The disintegrating speculations of an influential school of See also:criticism in See also:Germany were making their way among English men of culture just about the time, as is usually the See also:case, when the See also:tide was turning against them in their own See also:country. The See also:peculiar service which was rendered at this juncture by the ` Cambridge School' was that, instead of opposing a See also:mere dogmatic opposition to the See also: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 See also:life of Christian truth, and that his whole energies were employed in this inquiry because his whole See also:heart was engaged in the truths and facts which were at stake. He was not diverted by controversy to See also:side-issues; and his labour was devoted to the See also:positive elucidation of the sacred documents in which the Christian truth is enshrined." In 1872 the See also:anonymous publication of Supernatural See also:Religion created considerable sensation. In a See also:series of masterly papers in the Contemporary See also:Review, between See also:December 1874 and May 1877, Lightfoot successfully undertook the defence of the New Testament canon. The articles were published in collected See also:form in 1889. About the same time he was engaged in contributions to W. See also: He continued to work at his See also:editions of the Apostolic Fathers, and in 1885 published an edition of the Epistles of See also:Ignatius and See also:Polycarp,627 See also:collecting also a large store of valuable materials for a second edition of See also:Clement of See also: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 See also:health and shortened his splendid career at Durham. He was never married. He died at See also: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 See also:building erected to carry a See also:light for the purpose of warning or guidance, especially at See also:sea. I. See also:EARLY See also:HISTORY.—The earliest lighthouses, of which records exist, were the towers built by the Libyans and Cushites in See also:Lower See also:Egypt, See also:beacon fires being maintained in some of them by the priests. See also:Lesches, a See also:Greek poet (c.66o B.C.) mentions a lighthouse at Sigeum (now Cape Incihisari) in the See also:Troad. This appears to have been the first light regularly maintained for the guidance of mariners. The famous Pharos 1 of See also:Alexandria, built by Sostratus of See also:Cnidus in the reign of See also:Ptolemy II. (283–247 B.C.) was regarded as one of the wonders of the See also:world. The See also:tower, which took its name from that of the small See also:island on which it was built, is said to have been 600 ft. in height, but the See also:evidence in support of this statement is doubtful. It was destroyed by an See also:earthquake in the 13th See also:century, but remains are said to have been visible as See also:late as 1350. The name Pharos became the general See also:term for all lighthouses, and the term " pharology " has been used for the See also:science of lighthouse construction.
The tower at See also:Ostia was built by the See also:emperor See also:Claudius (A.D. 50). Other famous See also:Roman lighthouses were those at See also:Ravenna, See also:Pozzuoli and See also:Messina. The See also:ancient Pharos at See also:Dover and that at See also:Boulogne, later known as la Tour d'Ordre, were built by the See also:Romans and were probably the earliest lighthouses erected in western Europe. Both are now demolished.
The light of Cordouan, on a See also:rock in the sea at the mouth of the See also:Gironde, is the earliest example now existing of a See also:wave-swept tower. Earlier towers on the same rock are attributed the first to See also: 805) and the second to Edward the See also:Black Prince. The existing structure was begun in 1584 during the reign of See also:Henri II. of See also:France and completed in 1611. The upper See also:part of the beautiful See also: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 See also:focal See also:plane of the light 196 ft. above high See also:water (fig. I). Until the 18th century the light exhibited from the tower was from an See also:oak See also:log See also:fire, and subsequently a See also:coal fire was in use for many years. The ancient tower at See also:Corunna, known as the See also:Pillar of See also:Hercules, is supposed to have been a Roman Pharos. The Torre del See also:Capo at See also:Genoa originally stood on the promontory of See also:San Berrique. It was built in 1139 and first used as a lighthouse in 1326. It was rebuilt on its See also:present site in 1643. This beautiful tower rises 236 ft. above the cliff, the light being elevated 384 ft. above sea-level. A See also:lens light was first installed in 1841. The Pharos of See also:Meloria was constructed by the Pisans in 1154 and was several times rebuilt until finally destroyed in 1290. On the See also:abandonment of Meloria by the Pisans, they erected the still existing tower at See also:Leghorn in 1304.
In the 17th and 18th centuries numerous towers, on which were erected braziers or grates containing See also:wood or coal fires, were established in various positions on the coasts of Europe. Among such stations in the See also:United See also:Kingdom were See also:Tynemouth (c. 16o8), the Isle of May (1636),.St See also:Agnes (168o), St Bees (1718) and the See also:Lizard (1751). The See also:oldest lighthouse in the United States is believed to be the See also:Boston light situated on Little See also:Brewster Island on the See also:south side of the See also:main entrance to Boston See also:Harbour, See also:Mass. It was established in 1716, the present structure dating from 1859. During the See also:American See also:War of See also:Independence the lighthouse suffered many vicissitudes and was successively destroyed and rebuilt three times by the American or See also:British
A full See also:account is given in See also:Hermann See also:Thiersch, Pharos Antike, See also:Islam and Occident (1909). See also See also:MINARET.
forces. At the third rebuilding in 1783 a See also: 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 See also:land structures. Wave-swept Towers.—In determining the See also:design of a lighthouse tower to be erected in a wave-swept position See also:consideration must be given to the See also:physical features of the site and its surroundings. Towers of this description are classified as follows: (i) See also:Masonry and See also:concrete structures; (2) Openwork See also:steel and See also:iron-framed erections on See also:pile or other See also:foundations; (3) See also:Cast iron plated towers; (4) Structures erected on See also:cylinder foundations. (I) Masonry Towers.—Masonry or concrete towers are generally preferred for erection on wave-swept rocks affording good See also:foundation, and have also been constructed in other situations where adequate foundations have been made by sinking caissons into a soft sea See also:bed. See also:Smeaton's tower on the Eddystone Rock is the See also: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 See also:low as possible. (b) The mass of the structure superimposed at any See also:horizontal See also:section must be sufficient to prevent its displacement by the combined forces of See also:wind and waves without dependence on the See also:adhesion at horizontal See also:joint faces or on the dovetailing of stones introduced as an additional safeguard. (c) The structure should be circular in See also: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 See also:direct horizontal stroke of the waves should, for preference, be constructed with See also:vertical See also:face. The upper portion to be either straight with See also:uniform See also:batter or continuously curved in the vertical plane. See also:External projections from the face of the tower, except in the case of a See also:gallery under the See also:lantern, should be avoided, the See also:surface throughout being smooth. (e) The height from sea-level to the See also:top of the tower should be sufficient to avoid the obscuration of the light by broken water or dense spray See also: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 See also:density and of resistant nature. (h) The stones used in the construction of the tower, at any See also:rate those on the See also:outer face, should be dovetailed or joggled one to the other in See also:order to prevent their being dislodged by the sea during the See also:process of construction and as an additional safe-guard of stability. Of late years, See also: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, See also:coral reefs and See also:sand See also: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) See also: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 See also:Diamond Shoal off Cape Hatteras on the See also: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 See also:lie about 14 M. off See also:Plymouth, are fully exposed to south-See also:west seas. The See also:reef is submerged at high water of See also: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 See also: It was a See also:frustum of a See also:cone 22 ft. 8 in. in diameter at the See also: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. See also: In 1877, owing partly to the undermining of the rock on which the tower was built and the insufficient height of the structure, the See also:Corporation of Trinity House determined on the erection of a explosive See also:gun-See also:cotton See also:fog See also: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-See also:wick burners, throwing a fixed light of 8000 See also:candle-See also:power over a danger known as the See also:Hand Deeps. The work of pre- paring the foundation was begun on the 17th of See also:July 1878, the foundation stone Foe°1 p,a,o being laid by the late See also:duke of See also:Edinburgh A -on the 19th of See also:August 1879. The last stone was laid on the 1st of See also: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 See also:Hoe, where it replaced the old Trinity House sea See also:mark. One of the See also: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 See also:rush See also: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 See also: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 See also: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 See also:wall and constituting solid portions thereof. In Smeaton's tower the floors consisted of stone See also: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 See also:place of Smeaton's tower Eddystone, New Lighthouse (J. N. See also: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 (See also:figs. 5 and 6) is a See also: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 See also:metal bolts. The tower contains 62,133 cub. ft. of See also: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 See also:pedestal of cast iron. The See also: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 See also:angle of 92° vertically. The 12 lens panels are arranged in See also:groups of two, thus producing a See also:group flashing light showing 2 flashes of 11 seconds' duration every See also:half See also:minute, the apparatus revolving once in 3 minutes. The burners originally fitted in the apparatus were of 6-wick See also:pattern, but these were replaced in 1904 by incandescent oil vapour burners. The intensity of the combined See also: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 See also: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 See also:system of constructing corbelled stone floors was first adopted by R. See also:Stevenson in the See also:Bell Rock lighthouse (fig. 8). Bell Rock Lighthouse (fig. 9).—The Bell Rock, which lies 12 m. off the coast of See also:Forfarshire, is exposed to a considerable extent at low water. The tower is submerged to a See also:depth of about 16 ft. at high water of spring tides. The rock is of hard See also:sandstone. The lighthouse was constructed by See also:Robert Stevenson and is See also: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 See also: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 See also:Tyree in See also:Argyllshire, are wholly open to the Atlantic. The work, designed by Alan Stevenson, was begun in 1838 and finished in 1844. The tower, the See also:pro-See also:file of which is a hyperbolic See also: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 See also: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 See also:floor. Haut Banc du See also:Nord Lighthouse.—This tower is placed on a reef at the See also: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 See also:February 185o, when the tower was ready for the erection of the lantern and See also:illuminating apparatus, a heavy storm swept away the whole of the structure. This tower was de-signed for an See also:elevation of 94 ft. to the focal plane. In 1851 the
erection of a granite tower, from the designs of James See also: 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 See also: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, See also: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 See also: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 See also:double flashing light of one minute See also: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 See also:Milford Haven, since 1776, when an oak pile structure was erected by Henry See also: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. See also: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 See also: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 See also: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 See also:Mull, which is the nearest See also: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, See also: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, See also:Lake See also:Huron.—This is a structure similar to that on Minot's ledge, See also:standing on a See also:limestone reef at the See also:northern end of the lake. The tower (fig. 16) was constructed with a view to withstanding the effects of See also:ice massing in solid See also: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 See also: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 See also:Calf of See also: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 See also:French Lighthouse Service, on the Ar'men Rock off the western extremity of the Ile de Sein, See also:Finistere, occupied fifteen years in construction (1867–1881). The rock is of small See also: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 See also:George's Reef Lighthouse, See also:California.—This structure consists of a square pyramidal stone tower rising from the easterly end of an See also:oval masonry See also: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 See also: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, See also: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-See also:horn worked by compressed See also:air. Fastnet Lighthouse.—In the year 1895 it was reported to the Irish See also:Lights Commissioners that the then existing lighthouse on the Fast-See also:net Rock off the south-west coast of See also:Ireland, which was completed in 1854 and consisted of a circular cast iron tower 86 ft. in height on the See also: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 See also:foreshore at the See also:foot of Beachy Head, near See also: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 See also: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 See also: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 See also:coffer-See also: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 See also:screw pile lighthouse erected on the Maplin Sand in the See also:estuary of the See also:river See also:Thames in 1838 is the earliest of its See also: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). See also:Fowey Rocks Lighthouse, See also: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 See also:accommodation of the keepers. The cost of construction amounted to £32,600 See also: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 See also:Trap Lighthouse.—This building was erected during the years 1893 and 1894 on Wolf Trap See also:Spit in Chesapeake See also: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 See also: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 See also:Bank in See also: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 See also:Weser (Germany), is a structure of great See also: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 See also:attempt, made in May 1883, to sink a caisson of bi-See also: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 See also: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 See also: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 (See also:Carlingford Lough, Ireland, 1823) ; Horsburgh (See also:Singapore, 1851) ; Bayes d'Olonne (Bay of See also:Biscay, 1861) ; Hanois (See also:Alderney, 1862) ; See also:Daedalus Reef, iron tower (Red Sea, 1863) ; Alguada Reef (Bay of See also:Bengal, 1865) ; Longships (Land's End, 1872) ; the Prongs (Bombay, 1874) ; Little Basses (Ceylon, 1878) ; the See also:Graves (Boston, U.S.A., M+ I: 4 4 I" III y%id -' ~io`M "Il~lf~I I _ JAI i "1A% ,\~-.~Ei ',See also:rye \, y/ aY~ III a. III ~~~. I I~ I `See also:IiL yin r an rs II11 Y' 4 14 % 11 i III ,t t gy//b7y% IH u. YE %/yir iw;eom w. 1 ` Matt ft, uw . H//~ I/B i///////W&AW, i' °may/Y.(!s'W L \\\~a\\\\~. 111 . \Q\Q\\~` \Han IfOigO////// %t /i djj steal ;' i''/b%/ /i%//y %\ 4 ° .''m /e///A-r_,~m%//%i%H y~)m //0g4f'' ~////~//\/~/,// % %//~//A %%%a'1,0 %%/iii% *#IBM%%////%%\//~//bf/% /// M%///, " i m f /%. \\\\\\~~~\ r W~~, //////~ay ;,man\ \ wmkw' q~/h y//Ik H.W L.W. 1IRVICN ROOM. Additional information and CommentsThere are no comments yet for this article.
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