Page:EB1911 - Volume 16.djvu/672

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
650
LIGHTHOUSE


Table VII.Typical Non-Electric Lighthouse Apparatus.

Name. Locality. Character-
istic.
 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 Estab-
 lished.* 
Remarks.
      Secs. Secs.   mm.         Feet.    
Casquets Channel Islands 3 flash 30 1.5 185,000 920 1 : 9  Incandescent 
petroleum vapour
“Matthews” 3-50 mm. dia. mantles 3300 120 1877  Dioptric holophote, 1261/2° vertical angle; 3 sides of 3 panels in each.
Eddystone South Devon 2 flash 30 1.5 292,000 920 1 : 12 do. do. 3300 133 1882  Biform apparatus, lens elements only, 92° vertical angle; 6 sides of 2 panels each.
Bishop Rock Scilly Isles 2 flash 60 4.0 622,000 1330 1 : 10 do. do. 3300 134 1886  Biform apparatus, lens elements only, 80° vertical angle; 5 sides of 2 panels each.
Spurn Point Yorkshire Single flash 20 1.5 519,000 1330 1 : 6 do. do. 3300 120 1895  Lens elements only, 80° vertical angle.
Lundy Island Bristol Channel 2 flash 20 .33 374,000 920 Nearly 1 : 4 do. do. 3300 165 1897  Mercury rotation, 4-panel bivalve.
[St. Mary’s Isle, Northumberland (1898), is similar.]
Pendeen Cornwall 4 flash 15 .25 190,000 920 1 : 8 do. do. 3300 195 1900  80° vertical angle lens, 2 sides of 4 panels each, mercury rotation.
Roker Pier Sunderland Single flash 5 .10 175,000 500 Nearly 1 : 2 do. “Chance” 55 mm. dia. mantle 1200 83 1903  Mercury rotation; univalve 164° in azimuth, with 164° dioptric mirror in rear.
Bell Rock Near Firth of Tay Red and white
flashes alter-
nately every
30 secs.
60 .50 392,000 920 and 1330  White about 
1 : 9
red about
1 : 2.2
do. “Chance” 55 mm. dia. mantle 1200 93 1902  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.]
Kinnaird’s Head Aberdeenshire Single flash 15 .50 881,000 920 and 1330 1 : 2.2 do. do. 2150 120 1903  Composite apparatus; panels of 1330 mm. and 920 mm. focal distance; 2 faces.
Tarbet Ness Dornoch Firth 6 flash 30 .50 89,000 700 1 : 12 do. “Chance” 55 mm. dia. mantle 1200 175 1892  6 panels (lens) of 30° with 180° mirror.
[Douglas Head (Isle of Man) similar.]
Sule Skerry West of Orkneys 3 flash 30 1.0 378,000 1330 1 : 9 do. “Chance” 85 mm. dia. mantle 2150 113 1895  Equiangular lenses.
Pladda South end of Arran Island 3 flash 30 .50 597,000 1330 1 : 6 do. do. 2150 130 1901  3 equiangular lens panels with mirror in rear; side panels eccentric.
[Hyskin Rocks (1904) similar.]
Tory Island Co. Donegal 3 flash 60 3.0 17,000 to 326,000 1330 1 : 6 Coal Gas Wigham, 108 jets (maximum) 2300 (max.) 130 1887  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.
Fastnet Co. Cork Single flash 5 .17 750,000 920 1 : 4  Incandescent 
petroleum vapour
Irish pattern 50 mm. mantle 1200 160 1904  Biform apparatus; 4 panels of 90° vertical angle and 90° in azimuth; mercury rotation.
Kinsale do. 2 flash 10 .25 460,000 920 1 : 6 do. do. 1200 236 1907  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.]
Howth Bailey Dublin Bay Single flash 30 1.0 950,000 920 13 : 32 do. Irish pattern 3-50 mm. dia. mantles 3300 134 1902  Bivalve apparatus; panels of 147° in azimuth and 122° vertical angle; mercury rotation.
Chassiron Bay of Biscay Single flash 10 1.0 70,000 920 1 : 8 Oil 6 wick 480 164 1891 The old first-order apparatus has been utilized in all cases.
.50 180,000 920 1 : 8  Incandescent 
oil gas
30 mm. dia. mantle 400 164 1895
.70 360,000 920 1 : 8  Incandescent 
acetylene
55 mm. dia. mantle 1300 164 1902
Cap d’Antifer English Channel Single flash 20 1.0 400,000 1330 1 : 6  Incandescent 
petroleum vapour
French pattern 85 mm. mantle 2150 394 1894  Mercury rotation, hyper-radial apparatus with reflecting prisms. This is the only apparatus of this focal distance on the French coast.
Île de Batz Finistère 4 flash 25 .37 200,000 920 1 : 8 do. do. 2150 223 1900  Group-flashing apparatus; 4 panels of 45°, with 180° mirror in rear; mercury rotation.
Ar’men do. 3 flash 20 .38 200,000 700 1 : 5 do. do. 2150 94 1897  Mercury rotation; 3 panels, mirror in rear.
Villefranche Mediterranean Single flash  5 .38 250,000 700 1 : 4 do. do. 2150 229 1902  Mercury rotation.
Île Vierge Finistère Single flash  5 .38 500,000 700 1 : 4 do. do. 2150 252 1902  Twin optic; mercury rotation.
Kennery Island Bombay 2 flash 10 .25 250,000 920 Nearly 1:4 do. 70 mm. dia. mantle 1400 153 1902  Mercury rotation; bivalve apparatus; 2 double-flashing 170° panels.
Cape Race Newfoundland Single flash 7.5 .30 1,100,000 1330 1 : 4 do. “Chance” 85 mm. dia. mantle 2150 165 1907  4 panels, vertical angle 1211/2°; mercury rotation.
[Manora Point, Karachi, 1909, similar.]
Pachena Point British Columbia 2 flash 7.5 .44 220,000 920 1 : 8 do. do. 2150 .. 1908  Mercury rotation. 4 sides of 2 panels each.
Cape Hermes Cape Colony Single flash  3 .31 30,000 250 1 : 3 do. “Chance” 55 mm. dia. mantle 1200 175 1904  3 panels, vertical angle 150°; mercury rotation.
Hood Point do. 4 flash 40 .58 200,000 920 1 : 8 do. “Chance” 85 mm. dia. mantle 2150 180 1895  Mercury rotation; 4 panels of 45° in azimuth and 80° vertical angle, with catadioptric mirror in rear.
Cape Naturaliste West Australia 2 flash 10 .15 450,000 920 About 1 : 3 do. do. 2150 404 1904  Mercury rotation; 2 lenses of 1261/2° in azimuth, with mirror of 107°.
Point Cloates do. Single flash  5 .30 300,000 700 1 : 3 do. do. 2150 190 1909  Mercury rotation; 3 panels, each 120° in azimuth and 1331/2° vertical angle.
Pecks Ledge Connecticut, U.S.A. 2 flash 30 .50 10,000 250 1 : 4 do. 34 mm. dia. mantle 300 54 1906  Rotated on ball bearings. 2 lenses of 90° each and mirror.
Fire Island New York, U.S.A. Single flash 60 4.0 250,000 920 1 : 8 do. 55 mm. dia. mantle 1000 167 1858  Rotated on roller bearings.
Gray’s Harbor Washington, Pacific Coast, U.S.A. Alternating
red and white
flashes
 5 .20 White 10,000 red 8,000 500 .. Oil 3 wick 160 122 1898  Mercury 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.