THE NATIONAL GEOGRAPHIC MAGAZINE 



403 



Photograph by F. C. Ilingsburg 



THE BEGINNING OF THE CONSTRUCTION OF THE TALE LIGHTHOUSE, SHOWING THE 

 STEEL REINFORCEMENT IN PLACE FOR THE FOUNDATION 

 AND BASE OF THE TOWER 



The steel skeleton, around which the concrete of the tower was poured, consists of 40 

 vertical steel bars, banded by a spiral of round steel bars, with loops one foot apart, wired 

 to each vertical bar. 



this passage, threatening mariners since 

 the days of the early voyagers, these 

 great rays now flash out friendly guid- 

 ance to the seamen of all countries, re- 

 gardless of nationality; the beams of this 

 light have been seen 29 sea miles away, 

 reaching nearly to the Haitian coast, and 

 they sweep a sea area of about 2,200 

 square statute miles, as large as the State 

 of Delaware. 



Navassa light, on this rock in the center 

 of one of the principal international sea 

 passages and 500 miles from the Amer- 

 ican coast, is the most important light- 

 house built by the United States in the 

 last quarter century. 



A TOWER TO WITHSTAND HURRICANES 

 AND EARTHQUAKES 



Navassa Island has the outline of an 

 oyster shell and is slightly more than a 



mile in area. As the island rises fairly 

 abruptly on all sides, forming a roughly 

 flat tableland about 200 feet above the 

 sea, it was necessary to build a tower 150 

 feet in height, in order that the light 

 might "see over" the edge of the plateau 

 and not be obscured to vessels in the 

 vicinity of the island, unless close under 

 the cliffs. The tower was placed on the 

 highest part, bringing the light 395 feet 

 above the sea. 



The lighthouse tower was designed to 

 withstand West India hurricanes as well 

 as earthquakes, and the lower sections 

 have massive proportions, the base being 

 25 feet in diameter, with walls over 6 

 feet thick. It is built of reinforced con- 

 crete, one of the tallest towers yet con- 

 structed by this method ; it is of simple 

 and dignified design, bell-shaped at the 

 base, and above that a simple cylinder to 



