■arr- STfafcmxaB 



TllK CllAXDKLKL'R LlCllT-TOWKK, I.OUISI A.\ A, WHICH WAS AliAXDON KD AFTKR BEIXr. 



UNDER^rIXl•:n v.y a tornado ix 1893 



lighthouses, as the brilliant light so at- 

 tracts them that they will fly directly for 

 it, and striking the heavy glass of the 

 lantern are killed and fall to the ground. 

 At Cape Charles light the keeper has 

 seen ducks tly directly through the lan- 

 tern and fall to the floor cut and torn by 

 the broken glass. Some lighthouses are 

 fitted with bird-protecting screens around 

 the lantern, as for instance at Mayo 

 Beach light on Cape Cod. When Sabine 

 Bank light, in the Gulf of Mexico, was 

 increased in brilliancy by installing an 

 oil vapor lamp, a bird-guard was found 

 necessary because of the birds flying for 

 the lantern, attracted by the more bril- 

 liant light. 



FROM WOOD FIRKS AXD CAXOLKS TO OIL 

 V.\POR .VXD KLIvCTRIC L.\.MPS 



The early lighthouses were lighted by 

 wood or coal fires burned in open bra- 

 ziers, and later by candles inclosed in 

 lanterns ; the resulting light was neces- 

 sarily weak and fitful, and a large part 

 was lost by being diffused in directions 

 of no use to mariners. A coal fire was 

 burned at the Isle of May light on the 

 coast of Scotland U]) to 1816. and the 

 famous Eddystone was lighted with 24 



wax candles to 181 1. Oil lamps were 

 early used in this country, if not from 

 the first lighting of Boston light. Fisii 

 oil, sperm oil. colza oil, lard oil, and 

 mineral oil were in turn burned, increas- 

 ing expense in each case compelling a 

 change. Circular wick lamps, with a 

 central current of air, were invented by 

 Argand in 1782. 



At the present time lamps with from 

 one to five concentric wicks, and burn- 

 ing a high grade of kerosene oil. are used 

 in a majority of lighthouses. About 

 610,000 gallons of oil are burned each 

 vear at the light stations of the United 

 States, about 340,000 gallons of which 

 are for lighthiiuse illumination. 



For the more important lights the in- 

 candescent oil vapor lamp is now used, 

 having been introduced by the French 

 in 1898. In this lamp the oil is heated 

 and then vaporized, and is burned mixed 

 with air under a mantle which is made 

 incandescent. This gives a nnich more 

 brilliant light than the wick lamp, with 

 a smaller consumption of oil. 



For instance, this change of lam])s 

 recently made at Cape Hatteras light 

 has increased the brilliancy of the light 

 from 34.000 to 160,000 candle power. 



31 



