11.Lighthouse Administration.The principal countries of the world possess organized and central authorities responsible for the installation and maintenance of coast lights and fog signals, buoys and beacons.
United Kingdom.—In England the corporation of Trinity House, or according to its original charter, “The Master Wardens, and Assistants of the Guild Fraternity or Brotherhood of the most glorious and undivided Trinity and of St Clement, in the Parish of Deptford Strond, in the county of Kent,” existed in the reign of Henry VII. as a religious house with certain duties connected with pilotage, and was incorporated during the reign of Henry VIII. In 1565 it was given certain rights to maintain beacons, &c., but not until 1680 did it own any lighthouses. Since that date it has gradually purchased most of the ancient privately owned lighthouses and has erected many new ones. The act of 1836 gave the corporation control of English coast lights with certain supervisory powers over the numerous local lighting authorities, including the Irish and Scottish Boards. The corporation now consists of a Master, Deputy-master, and 22 Elder Brethren (10 of whom are honorary), together with an unlimited number of Younger Brethren, who, however, perform no executive duties. In Scotland and the Isle of Man the lights are under the control of the Commissioners of Northern Lighthouses constituted in 1786 and incorporated in 1798. The lighting of the Irish coast is in the hands of the Commissioners of Irish Lights formed in 1867 in succession to the old Dublin Ballast Board. The principal local light boards in the United Kingdom are the Mersey Docks and Harbour Board, and the Clyde Lighthouse Trustees. The three general lighthouse boards of the United Kingdom, by the provision of the Mercantile Marine Act of 1854, are subordinate to the Board of Trade, which controls all finances.On the 1st of January 1910 the lights, fog signals and submarine bells in service under the control of the several authorities in the United Kingdom were as follows:Light-houses.Light-vessels.FogSignals.SubmarineBells.Trinity House116519712Northern Lighthouse Commissioners138544..Irish Lights Commissioners9311353Mersey Docks and Harbour Board166132Admiralty3126..Clyde Lighthouse Trustees1415..Other local lighting authorities80911892Totals12178728919Some small harbour and river lights of subsidiary character are not included in the above total.United States.—The United States Lighthouse Board was constituted by act of Congress in 1852. The Secretary of Commerce and Labor is the ex-officio president. The board consists of two officers of the navy, two engineer officers of the army, and two civilian scientific members, with two secretaries, one a naval officer, the other an officer of engineers in the army. The members are appointed by the president of the United States. The coast-line of the states, with the lakes and rivers and Porto Rico, is divided into 16 executive districts for purposes of administration.The following table shows the distribution of lighthouses, light-vessels, &c., maintained by the lighthouse board in the United States in June 1909. In addition there are a few small lights and buoys privately maintained.Lighthouses and beacon lights1333Light-vessels in position53Light-vessels for relief13Gas lighted buoys in position94Fog signals operated by steam or oil engines228Fog signals operated by clockwork, &c.205Submarine signals43Post lights2333Day or unlighted beacons1157Bell buoys in position169Whistling buoys in position94Other buoys5760Steam tenders51Constructional Staff318Light keepers; and light attendants3137Officers and crews of light-vessels and tenders1693France.—The lighthouse board of France is known as the Commission des Phares, dating from 1792 and remodelled in 1811, and is under the direction of the minister of public works. It consists of four engineers, two naval officers and one member of the Institute, one inspector-general of marine engineers, and one hydrographic engineer. The chief executive officers are an Inspecteur Général des Ponts et Chaussées, who is director of the board, and another engineer of the same corps, who is engineer-in-chief and secretary. The board has control of about 750 lights, including those of Corsica, Algeria, &c. A similar system has been established in Spain.Table VI.—Electric Lighthouse Apparatus.Name.Characteristic.Period.Duration of Flash.Candle-power (Service Intensity).Focal Distance of Lens.Ratio of Angular Breadth of Panel to Whole Circle.Current.Voltage.Carbons.Electric Generators.Lamps.Engins.Elevation above High Water.Year Established.Remarks.Secs.Secs.Standard Candles.mm.Amps.mm.Feet.United Kingdom—Souter Point(Durham)Single flash305Candle-power not officially determined.5001 : 8..4017Holmes machines, alternating (400 revs.)SerrinSteam1501871Fixed light apparatus, with revolving vertical condensing lenses in eight panels.South Foreland(Kent)Single flash2.5.357001 : 16..4026do.SerrinSteam3741904Lens elements only; 97° vertical angle. (This apparatus was in use at St Catherine’s, 1888 to 1904, and replaced the two fixed electric lights established in 1872.)Lizard(Cornwall)Single flash3.137001 : 4145 for 50 mm. carbons4050 and 60 flutedDe Meritens alternators (600 revs.)Modified Berjot-SerrinOil engines2301903Mercury rotation; vertical angle, 139°. Replaced the two fixed electric lights erected in 1878.St Catherine’s(Isle of Wight)Single flash5.217001 : 4145 for 50 mm. carbons4050 and 60 fluteddo.do.2 Steam, each 50 h.p.1361904Mercury rotation; vertical angle, 139°.Isle of May(Firth of Forth)4 flash30.4700 (Fixed apparatus)1 : 82204040do.Berjot-SerrinSteam2401886Fixed light apparatus, with revolving vertical condensing lenses.France—Dunkerque(Strait of Dover)2 flash10.2 to .43,500,000 to 6,500,0003001 : 1230 and 604514 and 182 De Meritens alternators, each of 5.5 k.w. (550 revs.)Improved Serrin2 Semi-portable steam, each 30 i.h.p.1931902Twelve panels in groups of two. (This apparatus was in use at Barfleur, 1893 to 1902.)Calais(Strait of Dover)[Les Baleines (1882) similar]4 flash15.75900,0003001 : 24604518do.French Service pattern (1902)do.1901883Fixed light apparatus, with revolving vertical condensing prisms.Cap Gris-nez(Strait of Dover)Single flash5.10 to .1415,000,000 to 30,000,0003001 : 460 to 1204518 and 28do.do.Steam2331899Twin optic, mercury rotation. (This light superseded a triple-flashing electric light, with intermediate red flash, of the Calais type, established in 1885. The first installation of the electric light at this station was in 1869.)La Canche(Strait of Dover)2 flash10.10 to .1415,000,000 to 30,000,0003001 : 430 to 604514 and 18do.do.do.1741900Twin optic, mercury rotation. (This light superseded a fixed electric light established in 1884.)Cap de la Hève(Havre, English Channel)[Île d’Yeu in the Bay of Biscay (1895) similar]Single flash5.10 to .1410,000,000 to 20,000,0003001 : 460 to 1204518 and 28De Meritens alternators (550 revs.)Improved Serrindo.3971893Mercury rotation. (The first installation of electric light at this lighthouse was in 1863.)Créac’h d’Ouessant(Ushant)[Barfleur (English Channel) 1903, La Coubre (Bay of Biscay) 1905, and Belle Île (Bay of Biscay) 1903, similar]2 flash10.10 to .1415,000,000 to 30,000,0003001 : 460 to 1204518 and 282 De Meritens alternators, each of 5.5 k.w. (550 revs.)French Service pattern (1902)do.2251901Twin optic, mercury rotation. (This light superseded a double-flashing electric light, similar to that now at Dunkerque, established in 1888.)Penmarc’h(Phare d’Eckmühl)(Finistère)Single flash5.10 to .1415,000,000 to 30,000,0003001 : 430 and 604514 and 18Two-phase Labour alternators (810 to 820 revs.)do.do.1971897Twin optic, mercury rotation.Planier(near Marseilles)Single flash5.10 to .1415,000,000 to 30,000,0003001 : 430 to 604514 to 18De Meritens alternators (550 revs.)do.do.2071902Twin optic, mercury rotation. (This light superseded an electric light established in 1881, showing a group of three white flashes separated by one red flash of the Calais type.)Italy—Tino(Gulf of Spezia)3 flash301.25Undetermined.7001 : 2450 110 2005015 25 35do.(830 revs.)Berjot-Serrindo.3841885Eight panels of three lenses each, no mirror.America—Navesink(Entrance to New York Bay)Single flash5.08About 60,000,000700Nearly 1 : 2Max. 1005023Alternating dynamos (800 revs.)Modified Serrin (Ciolina)Oil, each 25 h.p.2461898Mercury rotation. Bivalve of 165°.Australia—Macquarie(Sydney, N.S.W.)Single flash6085,000,0009201 : 1655 1105015 25De Meritens alternators (600 revs.)SerrinGas345188316-panel revolving apparatus, with 180° fixed mirror.Table VII.—Typical Non-Electric Lighthouse Apparatus.Name.Locality.Characteristic.Period.Duration of Flashes.Candle-Power in Standard Candles (Service Intensity).Focal Distance of Lens.Ratio of Angular Breadth of Panel to Whole Circle.Illuminant.Burner.Service Candle-power of Burner.Height above High Water.Year Established.*Remarks.Secs.Secs.mm.Feet.CasquetsChannel Islands3 flash301.5185,0009201 : 9Incandescent petroleum vapour“Matthews” 3-50 mm. dia. mantles33001201877Dioptric holophote, 126½° vertical angle; 3 sides of 3 panels in each.EddystoneSouth Devon2 flash301.5292,0009201 : 12do.do.33001331882Biform apparatus, lens elements only, 92° vertical angle; 6 sides of 2 panels each.Bishop RockScilly Isles2 flash604.0622,00013301 : 10do.do.33001341886Biform apparatus, lens elements only, 80° vertical angle; 5 sides of 2 panels each.Spurn PointYorkshireSingle flash201.5519,00013301 : 6do.do.33001201895Lens elements only, 80° vertical angle.Lundy IslandBristol Channel2 flash20.33374,000920Nearly 1 : 4do.do.33001651897Mercury rotation, 4-panel bivalve.[St. Mary’s Isle, Northumberland (1898), is similar.]PendeenCornwall4 flash15.25190,0009201 : 8do.do.3300195190080° vertical angle lens, 2 sides of 4 panels each, mercury rotation.Roker PierSunderlandSingle flash5.10175,000500Nearly 1 : 2do.“Chance” 55 mm. dia. mantle1200831903Mercury rotation; univalve 164° in azimuth, with 164° dioptric mirror in rear.Bell RockNear Firth of TayRed and white flashes alternately every 30 secs.60.50392,000920 and 1330White about 1 : 9 red about 1 : 2.2do.“Chance” 55 mm. dia. mantle1200931902Combined hyper-radial and first-order light with back prisms in white and mirrors in red. Revolves in 60 secs.[Holy Island, 1905 (Lamlash), similar, flash every 15 secs.]Kinnaird’s HeadAberdeenshireSingle flash15.50881,000920 and 13301 : 2.2do.do.21501201903Composite apparatus; panels of 1330 mm. and 920 mm. focal distance; 2 faces.Tarbet NessDornoch Firth6 flash30.5089,0007001 : 12do.“Chance” 55 mm. dia. mantle120017518926 panels (lens) of 30° with 180° mirror.[Douglas Head (Isle of Man) similar.]Sule SkerryWest of Orkneys3 flash301.0378,00013301 : 9do.“Chance” 85 mm. dia. mantle21501131895Equiangular lenses.PladdaSouth end of Arran Island3 flash30.50597,00013301 : 6do.do.215013019013 equiangular lens panels with mirror in rear; side panels eccentric.[Hyskin Rocks (1904) similar.]Tory IslandCo. Donegal3 flash603.017,000 to 326,00013301 : 6Coal GasWigham, 108 jets (maximum)2300 (max.)1301887Triform apparatus, vertical angle of lenses 65°; 6 sides, one revolution in 6 minutes. The single flash from lens is divided by eclipsing burner into 3 flashes.FastnetCo. CorkSingle flash5.17750,0009201 : 4Incandescent petroleum vapourIrish pattern 50 mm. mantle12001601904Biform apparatus; 4 panels of 90° vertical angle and 90° in azimuth; mercury rotation.Kinsaledo.2 flash10.25460,0009201 : 6do.do.12002361907Biform apparatus, 3 sides each of 2 panels; vertical angle 96°; mercury rotation.[St. John’s Point, Co. Down (1908) similar, period 7.5 secs.]Howth BaileyDublin BaySingle flash301.0950,00092013 : 32do.Irish pattern 3-50 mm. dia. mantles33001341902Bivalve apparatus; panels of 147° in azimuth and 122° vertical angle; mercury rotation.ChassironBay of BiscaySingle flash101.070,0009201 : 8Oil6 wick4801641891The old first-order apparatus has been utilized in all cases..50180,0009201 : 8Incandescent oil gas30 mm. dia. mantle4001641895.70360,0009201 : 8Incandescent acetylene55 mm. dia. mantle13001641902Cap d’AntiferEnglish ChannelSingle flash201.0400,00013301 : 6Incandescent petroleum vapourFrench pattern 85 mm. mantle21503941894Mercury rotation, hyper-radial apparatus with reflecting prisms. This is the only apparatus of this focal distance on the French coast.Île de BatzFinistère4 flash25.37200,0009201 : 8do.do.21502231900Group-flashing apparatus; 4 panels of 45°, with 180° mirror in rear; mercury rotation.Ar’mendo.3 flash20.38200,0007001 : 5do.do.2150941897Mercury rotation; 3 panels, mirror in rear.VillefrancheMediterraneanSingle flash5.38250,0007001 : 4do.do.21502291902Mercury rotation.Île ViergeFinistèreSingle flash5.38500,0007001 : 4do.do.21502521902Twin optic; mercury rotation.Kennery IslandBombay2 flash10.25250,000920Nearly 1:4do.70 mm. dia. mantle14001531902Mercury rotation; bivalve apparatus; 2 double-flashing 170° panels.Cape RaceNewfoundlandSingle flash7.5.301,100,00013301 : 4do.“Chance” 85 mm. dia. mantle215016519074 panels, vertical angle 121½°; mercury rotation.[Manora Point, Karachi, 1909, similar.]Pachena PointBritish Columbia2 flash7.5.44220,0009201 : 8do.do.2150..1908Mercury rotation. 4 sides of 2 panels each.Cape HermesCape ColonySingle flash3.3130,0002501 : 3do.“Chance” 55 mm. dia. mantle120017519043 panels, vertical angle 150°; mercury rotation.Hood Pointdo.4 flash40.58200,0009201 : 8do.“Chance” 85 mm. dia. mantle21501801895Mercury rotation; 4 panels of 45° in azimuth and 80° vertical angle, with catadioptric mirror in rear.Cape NaturalisteWest Australia2 flash10.15450,000920About 1 : 3do.do.21504041904Mercury rotation; 2 lenses of 126½° in azimuth, with mirror of 107°.Point Cloatesdo.Single flash5.30300,0007001 : 3do.do.21501901909Mercury rotation; 3 panels, each 120° in azimuth and 133½° vertical angle.Pecks LedgeConnecticut, U.S.A.2 flash30.5010,0002501 : 4do.34 mm. dia. mantle300541906Rotated on ball bearings. 2 lenses of 90° each and mirror.Fire IslandNew York, U.S.A.Single flash604.0250,0009201 : 8do.55 mm. dia. mantle10001671858Rotated on roller bearings.Gray’s HarborWashington, Pacific Coast, U.S.A.Alternating red and white flashes5.20White 10,000 red 8,000500..Oil3 wick1601221898Mercury rotation; one (red) lens of 170° in azimuth, reinforced by two 60° mirrors; one (white) lens of 60° in azimuth.* The dates given are of the establishment of the optical apparatus. In many cases incandescent burners have been installed at later dates.English Colonies.—In Canada the coast lighting is in the hands of the minister of marine, and in most other colonies the public works departments have control of lighthouse matters.Other Countries.—In Denmark, Austria, Holland, Russia, Sweden, Norway and many other countries the minister of marine has charge of the lighting and buoying of coasts; in Belgium the public works department controls the service.In the Trinity House Service at shore lighthouse stations there are usually two keepers, at rock stations three or four, one being ashore on leave. When there is a fog signal at a station there is usually an additional keeper, and at electric light stations a mechanical engineer is also employed as principal keeper. The crews of light-vessels as a rule consist of 11 men, three of them and the master or mate going on shore in rotation.The average annual cost of maintenance of an English shore lighthouse, with two keepers, is £275. For shore lighthouses with three keepers and a siren fog signal the average cost is £444. The maintenance of a rock lighthouse with four keepers and an explosive fog signal is about £760, and an electric light station costs about £1100 annually to maintain.A light-vessel of the ordinary type in use in the United Kingdom entails an annual expenditure on maintenance of approximately £1320, excluding the cost of periodical overhaul.Authorities.—Smeaton,Eddystone Lighthouse(London, 1793); A. Fresnel,Mémoire sur un nouveau system d’éclairage des phares(Paris, 1822); R. Stevenson,Bell Rock Lighthouse(Edinburgh, 1824); Alan Stevenson,Skerryvore Lighthouse(1847); Renaud,Mémoire sur l’éclairage et le balisage des côtes de France(Paris, 1864); Allard,Mémoire sur l’intensité et la portée des phares(Paris, 1876); T. Stevenson,Lighthouse Construction and Illumination(London, 1881); Allard,Mémoire sur les phares électriques(Paris, 1881); Renaud,Les Phares(Paris, 1881); Edwards,Our Sea Marks(London, 1884); D. P. Heap,Ancient and Modern Lighthouses(Boston, 1889); Allard,Les Phares(Paris, 1889); Rey,Les Progrès d’éclairage des côtes(Paris, 1898); Williams,Life of Sir J. N. Douglass(London, 1900); J. F. Chance,The Lighthouse Work of Sir Jas. Chance(London, 1902); de Rochemont and Deprez,Cours des travaux maritimes, vol. ii. (Paris, 1902); Ribière,Phares et Signaux maritimes(Paris, 1908); Stevenson, “Isle of May Lighthouse,”Proc. Inst. Mech. Engineers(1887); J. N. Douglass, “Beacon Lights and Fog Signals,”Proc. Roy. Inst.(1889); Ribière, “Propriétés optiques des appareils des phares,”Annales des ponts et chaussées(1894); Preller, “Coast Lighthouse Illumination in France,”Engineering(1896); “Lighthouse Engineering at the Paris Exhibition,” Engineer (1901-1902); N. G. Gedye, “Coast Fog Signals,”Engineer(1902);Trans. Int. Nav. Congress(Paris, 1900, Milan, 1905);Proc. Int. Eng. Congress(Glasgow, 1901, St Louis, 1904);Proc. Int. Maritime Congress(London, 1893); J. T. Chance, “On Optical Apparatus used in Lighthouses,”Proc. Inst. C.E.vol. xxvi.; J. N. Douglass, “The Wolf Rock Lighthouse,”ibid.vol. xxx.; W. Douglass, “Great Basses Lighthouse,”ibid.vol. xxxviii.; J. T. Chance, “Dioptric Apparatus in Lighthouses,”ibid.vol. lii.; J. N. Douglass, “Electric Light applied to Lighthouse Illumination,”ibid.vol. lvii.; W. T. Douglass, “The New Eddystone Lighthouse,”ibid.vol. lxxv.; Hopkinson, “Electric Lighthouses at Macquarie and Tino,”ibid.vol. lxxxvii.; Stevenson, “Ailsa Craig Lighthouse and Fog Signals,”ibid.vol. lxxxix.; W. T. Douglass, “The Bishop Rock Lighthouses,”ibid.vol. cviii.; Brebner, “Lighthouse Lenses,”ibid.vol. cxi.; Stevenson, “Lighthouse Refractors,”ibid.vol. cxvii.; Case, “Beachy Head Lighthouse,”ibid.vol. clix.;Notice sur les appareils d’éclairage(French Lighthouse Service exhibits at Chicago and Paris) (Paris, 1893 and 1900);Report on U.S. Lighthouse Board Exhibit at Chicago(Washington, 1894);Reports of the Lighthouse Board of the United States(Washington, 1852, et seq.); British parliamentary reports,Lighthouse Illuminants(1883, et seq.),Light Dues(1896),Trinity House Fog Signal Committee(1901),Royal Commission on Lighthouse Administration(1908);Mémoires de la Société des Ingénieurs Civils de France,Annales des ponts et chaussées(Paris);Proc. Inst. C. E.;The Engineer;Engineering(passim).
United Kingdom.—In England the corporation of Trinity House, or according to its original charter, “The Master Wardens, and Assistants of the Guild Fraternity or Brotherhood of the most glorious and undivided Trinity and of St Clement, in the Parish of Deptford Strond, in the county of Kent,” existed in the reign of Henry VII. as a religious house with certain duties connected with pilotage, and was incorporated during the reign of Henry VIII. In 1565 it was given certain rights to maintain beacons, &c., but not until 1680 did it own any lighthouses. Since that date it has gradually purchased most of the ancient privately owned lighthouses and has erected many new ones. The act of 1836 gave the corporation control of English coast lights with certain supervisory powers over the numerous local lighting authorities, including the Irish and Scottish Boards. The corporation now consists of a Master, Deputy-master, and 22 Elder Brethren (10 of whom are honorary), together with an unlimited number of Younger Brethren, who, however, perform no executive duties. In Scotland and the Isle of Man the lights are under the control of the Commissioners of Northern Lighthouses constituted in 1786 and incorporated in 1798. The lighting of the Irish coast is in the hands of the Commissioners of Irish Lights formed in 1867 in succession to the old Dublin Ballast Board. The principal local light boards in the United Kingdom are the Mersey Docks and Harbour Board, and the Clyde Lighthouse Trustees. The three general lighthouse boards of the United Kingdom, by the provision of the Mercantile Marine Act of 1854, are subordinate to the Board of Trade, which controls all finances.
On the 1st of January 1910 the lights, fog signals and submarine bells in service under the control of the several authorities in the United Kingdom were as follows:
Some small harbour and river lights of subsidiary character are not included in the above total.
United States.—The United States Lighthouse Board was constituted by act of Congress in 1852. The Secretary of Commerce and Labor is the ex-officio president. The board consists of two officers of the navy, two engineer officers of the army, and two civilian scientific members, with two secretaries, one a naval officer, the other an officer of engineers in the army. The members are appointed by the president of the United States. The coast-line of the states, with the lakes and rivers and Porto Rico, is divided into 16 executive districts for purposes of administration.
The following table shows the distribution of lighthouses, light-vessels, &c., maintained by the lighthouse board in the United States in June 1909. In addition there are a few small lights and buoys privately maintained.
France.—The lighthouse board of France is known as the Commission des Phares, dating from 1792 and remodelled in 1811, and is under the direction of the minister of public works. It consists of four engineers, two naval officers and one member of the Institute, one inspector-general of marine engineers, and one hydrographic engineer. The chief executive officers are an Inspecteur Général des Ponts et Chaussées, who is director of the board, and another engineer of the same corps, who is engineer-in-chief and secretary. The board has control of about 750 lights, including those of Corsica, Algeria, &c. A similar system has been established in Spain.
Table VI.—Electric Lighthouse Apparatus.
United Kingdom—
Souter Point(Durham)
Fixed light apparatus, with revolving vertical condensing lenses in eight panels.
South Foreland(Kent)
Lens elements only; 97° vertical angle. (This apparatus was in use at St Catherine’s, 1888 to 1904, and replaced the two fixed electric lights established in 1872.)
Lizard(Cornwall)
Mercury rotation; vertical angle, 139°. Replaced the two fixed electric lights erected in 1878.
St Catherine’s(Isle of Wight)
Mercury rotation; vertical angle, 139°.
Isle of May(Firth of Forth)
Fixed light apparatus, with revolving vertical condensing lenses.
France—
Dunkerque(Strait of Dover)
Twelve panels in groups of two. (This apparatus was in use at Barfleur, 1893 to 1902.)
Calais(Strait of Dover)[Les Baleines (1882) similar]
Fixed light apparatus, with revolving vertical condensing prisms.
Cap Gris-nez(Strait of Dover)
Twin optic, mercury rotation. (This light superseded a triple-flashing electric light, with intermediate red flash, of the Calais type, established in 1885. The first installation of the electric light at this station was in 1869.)
La Canche(Strait of Dover)
Twin optic, mercury rotation. (This light superseded a fixed electric light established in 1884.)
Cap de la Hève(Havre, English Channel)[Île d’Yeu in the Bay of Biscay (1895) similar]
Mercury rotation. (The first installation of electric light at this lighthouse was in 1863.)
Créac’h d’Ouessant(Ushant)[Barfleur (English Channel) 1903, La Coubre (Bay of Biscay) 1905, and Belle Île (Bay of Biscay) 1903, similar]
Twin optic, mercury rotation. (This light superseded a double-flashing electric light, similar to that now at Dunkerque, established in 1888.)
Penmarc’h(Phare d’Eckmühl)(Finistère)
Twin optic, mercury rotation.
Planier(near Marseilles)
Twin optic, mercury rotation. (This light superseded an electric light established in 1881, showing a group of three white flashes separated by one red flash of the Calais type.)
Italy—
Tino(Gulf of Spezia)
Eight panels of three lenses each, no mirror.
America—
Navesink(Entrance to New York Bay)
Mercury rotation. Bivalve of 165°.
Australia—
Macquarie(Sydney, N.S.W.)
16-panel revolving apparatus, with 180° fixed mirror.
Table VII.—Typical Non-Electric Lighthouse Apparatus.
Dioptric holophote, 126½° vertical angle; 3 sides of 3 panels in each.
Biform apparatus, lens elements only, 92° vertical angle; 6 sides of 2 panels each.
Biform apparatus, lens elements only, 80° vertical angle; 5 sides of 2 panels each.
Lens elements only, 80° vertical angle.
Mercury rotation, 4-panel bivalve.[St. Mary’s Isle, Northumberland (1898), is similar.]
80° vertical angle lens, 2 sides of 4 panels each, mercury rotation.
Mercury rotation; univalve 164° in azimuth, with 164° dioptric mirror in rear.
Combined hyper-radial and first-order light with back prisms in white and mirrors in red. Revolves in 60 secs.[Holy Island, 1905 (Lamlash), similar, flash every 15 secs.]
Composite apparatus; panels of 1330 mm. and 920 mm. focal distance; 2 faces.
6 panels (lens) of 30° with 180° mirror.[Douglas Head (Isle of Man) similar.]
Equiangular lenses.
3 equiangular lens panels with mirror in rear; side panels eccentric.[Hyskin Rocks (1904) similar.]
Triform apparatus, vertical angle of lenses 65°; 6 sides, one revolution in 6 minutes. The single flash from lens is divided by eclipsing burner into 3 flashes.
Biform apparatus; 4 panels of 90° vertical angle and 90° in azimuth; mercury rotation.
Biform apparatus, 3 sides each of 2 panels; vertical angle 96°; mercury rotation.[St. John’s Point, Co. Down (1908) similar, period 7.5 secs.]
Bivalve apparatus; panels of 147° in azimuth and 122° vertical angle; mercury rotation.
The old first-order apparatus has been utilized in all cases.
Mercury rotation, hyper-radial apparatus with reflecting prisms. This is the only apparatus of this focal distance on the French coast.
Group-flashing apparatus; 4 panels of 45°, with 180° mirror in rear; mercury rotation.
Mercury rotation; 3 panels, mirror in rear.
Mercury rotation.
Twin optic; mercury rotation.
Mercury rotation; bivalve apparatus; 2 double-flashing 170° panels.
4 panels, vertical angle 121½°; mercury rotation.[Manora Point, Karachi, 1909, similar.]
Mercury rotation. 4 sides of 2 panels each.
3 panels, vertical angle 150°; mercury rotation.
Mercury rotation; 4 panels of 45° in azimuth and 80° vertical angle, with catadioptric mirror in rear.
Mercury rotation; 2 lenses of 126½° in azimuth, with mirror of 107°.
Mercury rotation; 3 panels, each 120° in azimuth and 133½° vertical angle.
Rotated on ball bearings. 2 lenses of 90° each and mirror.
Rotated on roller bearings.
Mercury rotation; one (red) lens of 170° in azimuth, reinforced by two 60° mirrors; one (white) lens of 60° in azimuth.
English Colonies.—In Canada the coast lighting is in the hands of the minister of marine, and in most other colonies the public works departments have control of lighthouse matters.
Other Countries.—In Denmark, Austria, Holland, Russia, Sweden, Norway and many other countries the minister of marine has charge of the lighting and buoying of coasts; in Belgium the public works department controls the service.
In the Trinity House Service at shore lighthouse stations there are usually two keepers, at rock stations three or four, one being ashore on leave. When there is a fog signal at a station there is usually an additional keeper, and at electric light stations a mechanical engineer is also employed as principal keeper. The crews of light-vessels as a rule consist of 11 men, three of them and the master or mate going on shore in rotation.
The average annual cost of maintenance of an English shore lighthouse, with two keepers, is £275. For shore lighthouses with three keepers and a siren fog signal the average cost is £444. The maintenance of a rock lighthouse with four keepers and an explosive fog signal is about £760, and an electric light station costs about £1100 annually to maintain.
A light-vessel of the ordinary type in use in the United Kingdom entails an annual expenditure on maintenance of approximately £1320, excluding the cost of periodical overhaul.
Authorities.—Smeaton,Eddystone Lighthouse(London, 1793); A. Fresnel,Mémoire sur un nouveau system d’éclairage des phares(Paris, 1822); R. Stevenson,Bell Rock Lighthouse(Edinburgh, 1824); Alan Stevenson,Skerryvore Lighthouse(1847); Renaud,Mémoire sur l’éclairage et le balisage des côtes de France(Paris, 1864); Allard,Mémoire sur l’intensité et la portée des phares(Paris, 1876); T. Stevenson,Lighthouse Construction and Illumination(London, 1881); Allard,Mémoire sur les phares électriques(Paris, 1881); Renaud,Les Phares(Paris, 1881); Edwards,Our Sea Marks(London, 1884); D. P. Heap,Ancient and Modern Lighthouses(Boston, 1889); Allard,Les Phares(Paris, 1889); Rey,Les Progrès d’éclairage des côtes(Paris, 1898); Williams,Life of Sir J. N. Douglass(London, 1900); J. F. Chance,The Lighthouse Work of Sir Jas. Chance(London, 1902); de Rochemont and Deprez,Cours des travaux maritimes, vol. ii. (Paris, 1902); Ribière,Phares et Signaux maritimes(Paris, 1908); Stevenson, “Isle of May Lighthouse,”Proc. Inst. Mech. Engineers(1887); J. N. Douglass, “Beacon Lights and Fog Signals,”Proc. Roy. Inst.(1889); Ribière, “Propriétés optiques des appareils des phares,”Annales des ponts et chaussées(1894); Preller, “Coast Lighthouse Illumination in France,”Engineering(1896); “Lighthouse Engineering at the Paris Exhibition,” Engineer (1901-1902); N. G. Gedye, “Coast Fog Signals,”Engineer(1902);Trans. Int. Nav. Congress(Paris, 1900, Milan, 1905);Proc. Int. Eng. Congress(Glasgow, 1901, St Louis, 1904);Proc. Int. Maritime Congress(London, 1893); J. T. Chance, “On Optical Apparatus used in Lighthouses,”Proc. Inst. C.E.vol. xxvi.; J. N. Douglass, “The Wolf Rock Lighthouse,”ibid.vol. xxx.; W. Douglass, “Great Basses Lighthouse,”ibid.vol. xxxviii.; J. T. Chance, “Dioptric Apparatus in Lighthouses,”ibid.vol. lii.; J. N. Douglass, “Electric Light applied to Lighthouse Illumination,”ibid.vol. lvii.; W. T. Douglass, “The New Eddystone Lighthouse,”ibid.vol. lxxv.; Hopkinson, “Electric Lighthouses at Macquarie and Tino,”ibid.vol. lxxxvii.; Stevenson, “Ailsa Craig Lighthouse and Fog Signals,”ibid.vol. lxxxix.; W. T. Douglass, “The Bishop Rock Lighthouses,”ibid.vol. cviii.; Brebner, “Lighthouse Lenses,”ibid.vol. cxi.; Stevenson, “Lighthouse Refractors,”ibid.vol. cxvii.; Case, “Beachy Head Lighthouse,”ibid.vol. clix.;Notice sur les appareils d’éclairage(French Lighthouse Service exhibits at Chicago and Paris) (Paris, 1893 and 1900);Report on U.S. Lighthouse Board Exhibit at Chicago(Washington, 1894);Reports of the Lighthouse Board of the United States(Washington, 1852, et seq.); British parliamentary reports,Lighthouse Illuminants(1883, et seq.),Light Dues(1896),Trinity House Fog Signal Committee(1901),Royal Commission on Lighthouse Administration(1908);Mémoires de la Société des Ingénieurs Civils de France,Annales des ponts et chaussées(Paris);Proc. Inst. C. E.;The Engineer;Engineering(passim).
(W. T. D.; N. G. G.)
1A full account is given in Hermann Thiersch,Pharos Antike, Islam und Occident(1909). See alsoMinaret.2In 1901 one of the lights decided upon in 1886 and installed in 1888—Créac’h d’Ouessant—was replaced by a still more powerful twin apparatus exhibited at the 1900 Paris Exhibition. Subsequently similar apparatus to that at Créac’h were installed at Gris-Nez, La Canche, Planier, Barfleur, Belle-Île and La Coubre, and the old Dunkerque optic has been replaced by that removed from Belle-Île.3Both the Talais and Snouw light-vessels have since been converted into unattended light-vessels.4For the purposes of the mariner a light is classed as flashing or occulting solely according to the duration of light and darkness and without any reference to the apparatus employed. Thus, an occulting apparatus, in which the period of darkness is greater than that of light, is classed in the Admiralty “List of Lights” as a “flashing” light.5The Flamborough Head rocket was superseded by a siren fog signal in 1908.
1A full account is given in Hermann Thiersch,Pharos Antike, Islam und Occident(1909). See alsoMinaret.
2In 1901 one of the lights decided upon in 1886 and installed in 1888—Créac’h d’Ouessant—was replaced by a still more powerful twin apparatus exhibited at the 1900 Paris Exhibition. Subsequently similar apparatus to that at Créac’h were installed at Gris-Nez, La Canche, Planier, Barfleur, Belle-Île and La Coubre, and the old Dunkerque optic has been replaced by that removed from Belle-Île.
3Both the Talais and Snouw light-vessels have since been converted into unattended light-vessels.
4For the purposes of the mariner a light is classed as flashing or occulting solely according to the duration of light and darkness and without any reference to the apparatus employed. Thus, an occulting apparatus, in which the period of darkness is greater than that of light, is classed in the Admiralty “List of Lights” as a “flashing” light.
5The Flamborough Head rocket was superseded by a siren fog signal in 1908.
LIGHTING.Artificial light is generally produced by raising some body to a high temperature. If the temperature of a solid body be greater than that of surrounding bodies it parts with some of its energy in the form of radiation. Whilst the temperature is low these radiations are not of a kind to which the eye is sensitive; they are exclusively radiations less refrangible and of greater wave-length than red light, and may be called infra-red. As the temperature is increased the infra-red radiations increase, but presently there are added radiations which the eye perceives as red light. As the temperature is further increased, the red light increases, and yellow, green and blue rays are successively thrown off. On raising the temperature to a still higher point, radiations of a wave-length shorter even than violet light are produced, to which the eye is insensitive, but which act strongly on certain chemical substances; these may be called ultra-violet rays. Thus a very hot body in general throws out rays of various wave-length; the hotter the body the more of every kind of radiation will it throw out, but the proportion of short waves to long waves becomes vastly greater as the temperature is increased. Our eyes are only sensitive to certain of these waves, viz. those not very long and not very short. The problem of the artificial production of light with economy of energy is the same as that of raising some body to such a temperature that it shall give as large a proportion as possible of those rays which the eye is capable of feeling. For practical purposes this temperature is the highest temperature we can produce. As an illustration of the luminous effect of the high temperature produced by converting other forms of energy into heat within a small space, consider the following statements. If burned in ordinary gas burners, 120 cub. ft. of 15 candle gas will give a light of 360 standard candles for one hour. The heat produced by the combustion is equivalent to about 60 million foot-pounds. If this gas be burned in a modern gas-engine, about 8 million foot-pounds of useful work will be done outside the engine, or about 4 horse-power for one hour. If this be used to drive a dynamo for one hour, even if the machine has an efficiency of only 80%, the energy of the current will be about 6,400,000 foot-pounds per hour, about half of which, or only 3,200,000 foot-pounds, is converted into radiant energy in the electric arc. But this electric arc will radiate a light of 2000 candles when viewed horizontally, and two or three times as much when viewed from below. Hence 3 million foot-pounds changed to heat in the electric arc may be said roughly to affect our eyes six times as much as 60 million foot-pounds changed to heat in an ordinary gas burner.
Owing to the high temperature at which it remains solid, and to its great emissive power, the radiant body used for artificial illumination is usually some form of carbon. In an oil or ordinary coal-gas flame this carbon is present in minute particles derived from the organic substances with which the flame is supplied and heated to incandescence by the heat liberated in their decomposition, while in the electric light the incandescence is the effect of the heat developed by the electric current passed through a resisting rod or filament of carbon. In some cases, however, other substances replace carbon as the radiating body; in the incandescent gas light certain earthy oxides are utilized, and in metallic filament electric lamps such metals as tungsten or tantalum.
1.Oil Lighting
From the earliest times the burning of oil has been a source of light, but until the middle of the 19th century only oils of vegetable and animal origin were employed in indoor lamps for this purpose. Although many kinds wereVegetable and animal oils.used locally, only colza and sperm oils had any very extended use, and they have been practically supplanted by mineral oil, which was introduced as an illuminant in 1853. Up to the latter half of the 18th century the lamps were shallow vessels into which a short length of wick dipped; the flame was smoky and discharged acrid vapours, giving the minimum of light with the maximum of smell. The first notable improvement was made by Ami Argand in 1784. His burner consisted of two concentric tubes between which the tubular wick was placed; the open inner tube led a current of air to play upon the inner surface of the circular flame, whilst the combustion was materially improved by placing around the flame a chimney which rested on a perforated gallery a short distance below the burner. Argand’s original burner is the parent form of innumerable modifications, all more or less complex, such as the Carcel and the moderator.