THE EVOLUTION OF THE LIGHTSHIP. 117 



In other words, as the writer sees the matter, it would obviate the necessity of carrying 

 steam, at working pressure, 24 hours per day, seven days a week. It would obviate the car- 

 rying of much coal, as for the same horse-power required the oil would weigh half that of the 

 coal. Therefore, double the amount of energy could be stored upon the same ship in the 

 same space. 



It might also be found practical, instead of running the large engine to charge the stor- 

 age battery, to put in a small set, three or four kilowatts ; for charging the batteries and for 

 lighting the ship, it is quite possible that the smaller of the two large engines would run 

 often enough to keep the batteries well charged. 



The electrically-driven propeller would make the outfit as flexible as any steam plant, and 

 probably more flexible, and would be directly under the control of the operator in the pilot- 

 house, so that instant action could be had at any time. With the installation of the two sets it 

 will obviate almost entirely the possibility of a break-down. 



Mr. Cook (Communicated) : — Although not a member of the Society, I regret that I 

 was unable to attend the meeting and in person express my obligation for the generous at- 

 tention bestowed by the Secretary during the preparation of this paper, and the courtesy of 

 the Chairman and the various members who have considered the question here raised. 



I should have been glad indeed to receive the suggestions of shipbuilders and architects 

 who have built or designed vessels of this class, and would have presented such suggestions 

 to the proper authorities in connection with the designing of new lightships now under con- 

 sideration at Washington, so that a closer understanding between the two interested parties 

 could have been reached. 



With reference to the loss of the Trenton and the Vandalia, mentioned by Mr. Stevens, 

 I concur in the opinion of the Chairman that conditions will arise which may defeat the best 

 efforts in design and construction, and we can but do our best to make the possibility of de- 

 feat a remote one. Our Lighthouse Service met with such a loss in the hurricane of last No- 

 vember, when Lightvessel No. 82, off Buffalo, N. Y., foundered. The wreck has not yet 

 been found and an adequate analysis of the causes of the disaster cannot be made ; but the 

 violence of the storm was such that many other and larger vessels were also lost. With 

 regard to the position of the hawse pipe itself, I believe that the elevated pipe, as noted by 

 Mr. Stevens, is decidedly objectionable in the case of a small vessel in a strong current. 



I had understood that Naval Constructor Taylor was contemplating a series of experi- 

 ments on the rolling of vessels, and it is of great interest to learn from Mr. Sperry that this 

 work is actually under way. Mr. Taylor has very kindly spoken with me on the form, roll- 

 ing, and pitching of light vessels, and I trust that we may learn more from him as a result 

 of these experiments, which are of so comprehensive a character. 



The entrance of water through the hawse pipe is a source of great annoyance on the 

 modern lightship, as in the case of the Trenton, mentioned by Mr. Bull. Jackasses of va- 

 rious pliable materials have been tried, but were ground to pieces by the movement of the 

 chain, which, on a light vessel, is free to play over a range of several feet against the action 

 of the compressor springs, shown on Plate 58, with the surging of the vessel. A cast 

 steel ball-and-socket plug is now being designed to attach to the moving chain in way of the 

 hawse pipe, which, it is believed, will obviate this fault to a great extent. Several such 

 plugs will be supplied to a vessel, so that if the chain is paid out hurriedly in bad weather, 



