< Page:EB1911 - Volume 16.djvu
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, 12612° 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 12112°; 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 12612° 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 13312° 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.
This article is issued from Wikisource. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.