THE EVOLUTION OF THE LIGHTSHIP. 



By George Grouse Gook, Esq. 



[Read at the twenty-first general meeting of the Society of Naval Architects and Marine Engineers, held in 



New York, December 11 and 12, 1913.] 



INTRODUCTION. 



Of the many writers who have discussed the subject of sea marks none appears 

 to have assigned to the lightship a place wholly commensurate with its importance 

 as an aid to navigation or an example of engineering skill. A visit to the Library 

 of Congress, Washington, D. C, first indicated this, because I was there un- 

 able to find the specific title "The Lightship." Inquiry and search, however, yielded 

 many references in the evolution of this aid to navigation, from which I have 

 assembled the more important facts and endeavored to place them in logical order. 

 This record is far from complete, but it is my intention to add to it from time to 

 time until I have the full story of this bravest of little ships. 



The lightship is a beacon by day, a platform for the light by night, and a 

 sound signal station in time of fog. As a day mark, it may have any form ; it can 

 carry a light which throws out an unvarying beam to the horizon, and bear fog 

 signals of any type. Its efficiency in these capacities is established. In addition it 

 has certain important functions which are indicated in the following paragraphs : 



The lightship may be stationed in deep water many miles from land, and mark 

 a point from which arriving and departing vessels take bearings to proceed to 

 their destination. The Nantucket Lightship, now moored in i8o feet of water 43 

 miles from the nearest land, has been the landfall of transatlantic trade and travel 

 since 1855. 



The lightship may be moored on shifting shoals and banks where no founda- 

 tions for fixed structures could be laid. When the danger point of the shoal 

 shifts, a corresponding change is promptly made in the position of the light. The 

 Gull Stream Lightship on the Goodwin Sands ofif the southeast shore of Kent is 

 an excellent example. Nantucket and the Goodwins, with other points, similar in 

 many respects, have always been marked by the lightship. 



The landfall of the city of Milwaukee was marked by North Point Lighthouse 

 only for many years. Many wrecks were due to vessels holding in to the shore to 

 pick up the light and avoid running by the city. -Now Lightvessel No. 95 stands 

 three miles oflf the harbor entrance. It is an aid of strictly positive character, 

 showing the approaching mariner a place of security rather than warning him 

 from a danger point. His vessel will necessarily remain afloat where the lightship 



