LIGHTHOUSE ESTABLISHMENT, THE UNITED STATES. 



439 



lowered to its place, and through this disk the 

 first iron pile was driven. A perimeter disk 

 was then located by a gauge, and then the first 

 perimeter pile was driven through the center 

 of this disk. After every blow of the pile- 

 driver, the pile was tested with a plummet, and 

 the slightest deviation from the vertical was 

 rectified. In locating the disk for the next 

 perimeter pile, two gauges were used to get 

 the proper distance from the center pile, and 

 to maintain it from the perimeter pile just 

 driven. The disks were dragged along the bot- 

 tom until their outer edges just touched the 

 free edges of the gauges. Each pile was then 

 driven through the center of its disk. When 

 all were driven, their tops were leveled by cut- 

 ting off each to the line of the lowest. The 

 piles were then capped with their respective 

 sockets; the horizontal girders were inserted, 

 the diagonal tension- rods were placed and 

 screwed up, and the foundation series were 

 completed. Two months were occupied in 

 placing the wooden platform and this series. 

 During this time they had a smooth sea, but 

 after this time the main difficulty was the bad 

 weather. Finally, that problem was solved 



FOWEY ROCKS LIGHTHOUSE, FLORIDA REEF. 



by pitching tents on the working platform, 

 leaving a force of workmen there above the 

 running sea, supplied with material, and with 

 a small hoisting-engine to work their derrick 

 and their shears which had been erected in the 

 single day of good weather they had out of a 



month. The material was stored at Soldier 

 Key, four miles distant, and it was delivered 

 by lighters towed by a steam-launch, which 

 waited with steam up day and night to tow 

 them out when the weather would permit. On 

 March 16th the derrick and shears were set up, 

 and a cargo of iron delivered ; and in the 

 course of the next sixteen days five more car- 

 goes were landed on the platform, and the first 

 series of columns, girders, sockets, and tension- 

 rods was placed in position. On April 7th the 

 skeleton of the second series and the cylinder 

 to the top of the series was up ; and in an- 

 other week all the iron up to and including 

 the service-room floor was on the platform. 

 On April 30th the dwelling was finished; on 

 May 25th the illuminating apparatus was in 

 position, and on June 15th the work was com- 

 pleted and the light was exhibited. The whole 

 structure was completed in good time, despite 

 the trying circumstances accompanying its con- 

 struction. The preceding is a representation 

 of the lighthouse in question. 



The use of iron plates for building light- 

 houses on dry foundations, though not uncom- 

 mon abroad, mef early with little favor in 

 this country. But, in later years, when a great- 

 er knowledge of iron as a material for con- 

 struction was obtained, it came into larger 

 use. Among the more prominent of the iron 

 towers are those at Cape Canaveral, Florida, 

 designed in I860 and built in 1868, 150 feet 

 high ; that at Bolivar Point, Texas, built in 

 1872, 120 feet high; that at Hunting Island, 

 South Carolina, built in 1875, 130 feet high ; 

 and the tower now being erected at Cape 

 Henry, Virginia, which is to be 165 feet high. 

 The following description of the tower at 

 Hunting Island will show how these iron tow- 

 ers are put up, and this is a good specimen, 

 MS the necessity of taking it down to remove it 

 further back, if the encroachments of the sea 

 make it necessary, was considered at the time 

 of its erection. The shell of the tower is com- 

 posed of cast-iron panels of about twelve 

 hundred pounds weight each, of exactly the 

 same size, in each section, that they may each 

 occupy any position in the ring which they 

 form when put together. These panels vary in 

 thickness in the different sections, those of the 

 lower section being an inch and a half thick 

 and of the highest three quarters of an inch. 

 They are provided with flanges so as to con- 

 nect the several tiers of plates, and the plates 

 of each tier with each other by bolts through 

 them, and the flanges are made smooth, with 

 true planed surfaces. The base of the first tier 

 of panels consists of a flange three feet wide. 

 This flange extends one foot four inches be- 

 yond the outside of the tower. It is strength- 

 ened by bosses and vertical knees extending 

 upward to the top of the castings, which 

 contain the holes for the foundation-bolts. 

 The top flange is six inches by one and three 

 quarter inches. The lower flange of the sec- 

 ond section is one foot two inches wide. The 



