LIGHTHOUSE 



3426 



LIGHTHOUSE 



keepers of lights far from the mainland some- 

 times lead very lonely lives, and their faith- 

 fulness and heroism have often been praised 

 in song and story. Nothing more inspiring, 

 however, has ever been written than the true 

 story of Grace Darling, whose father kept the 

 lighthouse on Longstone, one of the Fame 

 Islands, and who risked her life to save the 

 survivors of a wreck on a neighboring reef. 



Great light towers, standing like sentinels at 

 the danger points of the ocean, make an -irre- 

 sistible appeal to the imagination. Such a 



(a) Cape Hatteras light station, North Carolina. 



(b) Saint George's Reef light .station, California. 



(c) "Rock of Ages" light, Lake Superior. 



(d) Sandy Hook light, New York. 



(e) Brenton Reef lightship, off Newport, R. I. 

 (/) Eddystone lighthouse, cross section view. 



The living rooms are near the top ; the bed- 

 rooms are on the floor below the light. 



lighthouse is the one which stands on Inchcape 

 or Bell Rock, off the east coast of Scotland, 

 on a dangerous reef in the North Sea, twelve 

 miles from land. The lighthouse was com- 

 pleted in 1810, and there is a tradition that 

 long before it was built sailors were warned of 

 their approach to the danger point by the 

 tolling of a bell, which had been placed on a 

 buoy by the good abbot of Aberbrothok. In 

 Southey's famous poem, The Inchcape Rock, 

 this legend is told in thrilling verse. 



The rock on which the Bell lighthouse stands 

 projects only a few feet above the water at 

 low tide, and when the builders began the 

 work of clearing the seaweed from the surface 

 they were forced to lie flat every few minutes 

 and cling to the weeds in order to keep from 

 being washed into the sea by the waves. After 

 the top was cleared, holes were drilled into 

 the rock, iron rods were driven into them, and 

 around the rods was built a strong iron plat- 

 form. Upon this the lighthouse, 115 feet high, 

 was built. 



The construction of the new lighthouse at 

 Beachy Head, on the southern coast of Eng- 

 land, was attended with equal difficulty. This 

 tower was built at the foot of a high cliff and 

 out in the open sea. A great hole was made 

 in the sea bottom, and at low tide the workers 

 built around the hole a thick, high wall, form- 

 ing an enclosure which was at all times pro- 

 tected from the sea. Within it were laid the 

 foundations of the lighthouse. A strong iron 

 platform, resembling a short pier, was built in 

 the sea as a workshop. Strong wire ropes car- 

 ried men, tools and materials from the top of 

 the cliff to the platform and back again, and 

 the blocks of granite which formed the stone- 

 work of the tower were all shaped and fitted 

 on land before they were permanently joined 

 together. It will thus be seen that lighthouse 

 building presents many engineering problems, 

 and could the story of every light tower be 

 told one might read a series of narratives of 

 absorbing interest. 



The Light. Inasmuch as the tower is erected 

 solely for the purpose of giving out light, the 

 lantern with its enclosed lamp is the most im- 

 portant part of the structure. In lighthouses 

 of modern construction the lantern consists of 

 a light, metallic frame which holds in position 

 a series of lenses (see LENS). These form its 

 sides. The largest lanterns are usually about 

 twelve feet in diameter and ten feet high, and 

 their light can be seen over the water for a 

 distance of twenty miles or more. The num- 

 ber of -sides or faces depends upon the style 

 of licht desired, this number varying from two 

 to eight. The center of each face contains a 

 large plano-convex lens which is surrounded 

 by a number of rings of prisms, so constructed 

 as to reflect in parallel lines all rays of light 

 which strike them. In the large lights the 

 number of these prisms runs into the thou- 

 sands. 



The lantern is mounted on a carriage which 

 moves on rollers or is floated in a tank of mer- 

 cury. When in use it is made to revolve by 

 clockwork, which is kept in motion by a sus- 

 pended weight. A beam of light can be seen 

 only when a face of the lantern is directly 

 opposite the observer; therefore when the lan- 

 tern revolves it gives out as many flashes as it 

 has sides. By covering any side with colored 

 glass a light of corresponding color can be seen. 

 Lighthouses show various kinds of signals, in- 

 cluding besides the flashing light the intermit- 

 tent, or occulting light, which is suddenly 

 turned on and off at varying intervals; the 





