no THE EVOLUTION OF THE LIGHTSHIP. 



pounds by two gunboat type boilers, 9 feet 3 inches in diameter, and 16 feet 4^ 

 inches long. Under fair conditions some 360 indicated horse-power is developed 

 and a speed of 10 knots obtained. > 



The actual usefulness of such a plant has been again and again demonstrated 

 in emergencies, and its absence has been the indirect cause of many a disaster. One 

 such case was that of a German lightship at the mouth of the Elbe, which broke 

 from its moorings and was driven helplessly ashore. All members of the crew 

 were lost. The utility of the propelling plant may be better judged, however, by 

 the fact that the U. S. lightvessel in the strong current of the Gulf Stream, over the 

 shifting sands of Diamond Shoal, has steamed on an average of over 300 miles per 

 month throughout the period of a year. 



Another important improvement in design consisted in fixing the lanterns per- 

 manently aloft, and was suggested, no doubt, by their early increase in size and 

 weight, which made it difficult to raise and lower them as required for their proper 

 operation. This plan, also, is an old one. It was proposed in England in 1845. 

 Reference to the files of the U. S. Bureau of Lighthouses discloses the fact that a 

 similar proposal was made there at about the same time for a vessel with two 

 lights fixed aloft. It seems this proposition was more favorably received than 

 many early ones now so universal, for Major Eliot, of the U. S. Lighthouse Board, 

 reported in 1873 the construction of a lightship in England fitted with a hollow 

 steel mast containing a ladder inside for access to the lantern. 



A variation from the tubular steel mast is that of one built of angles or 

 other structural shapes. The first of this type proposed is found on a plan sub- 

 mitted to the U. S. Lighthouse Board in 1873 by Henry Lepaute, Constructeur, of 

 Paris. 



Lanterns fixed aloft upon one mast or the other, of these types, are now gen- 

 erally employed in all new work. The latest development of the open work class 

 is used on the U. S. Lightvessel No. 44, which has been recently fitted with these 

 masts, and stationed at Northeast End, New Jersey. The present tubular type was 

 brought into current use by the French on the Talais of 1896, and it is similar in 

 general characteristics to those proposed in 1845. Its use is also shown on the 

 plates of the U. S. Lightvessel No. 94, published herewith. 



In all the main parts of the lightship meant to accommodate the crew, who 

 spend their lives on board, and add to their comfort, the greatest progress has been 

 made. One of the most important steps was taken in fitting the vessel with a com- 

 plete upper or spar deck, extending throughout its entire length. Nearly all early 

 ships were but single-deck vessels, in which the crew lived on a lower deck or plat- 

 form below the water line. The first step came in the building up of the sides of the 

 vessel forward, and the laying of a forecastle deck to protect the windlass, and such 

 parts of the quarters as could be placed there. An extension of this forecastle, both 

 in length and height, naturally followed, and in 1894 U. S. Lightvessel No. 58 was 

 built with an entire upper or spar deck. In such a design, the quarters for both the 

 officers and men are placed on the main deck, well above the water line, and they 



