LIGHTHOUSE ESTABLISHMENT, THE UNITED STATES. 



449 



not requiring the greatest intensity and power springs throw the ball from the bell after each 

 of sound. It is the ordinary locomotive whis- blow, permitting vibration, and causing the 



tie, of a varying diameter, from six to eighteen 

 inches, operated by steam from an ordinary 

 and often an upright boiler, with a pressure 

 of from fifty to one hundred pounds to the 

 square inch. It can be made to produce any 

 combination of shrieks, in a given time, so that 

 it can be identified by its published character- 

 istic. These are produced and regulated auto- 

 matically by an engine taking its steam from 

 the same boiler, which, at arranged intervals, 

 opens and closes the valves, thus shutting off 

 or letting on the steam. The machinery is 

 simple and the piston-pressure quite light ; 

 and, while it is not liable to get out of order, 

 it requires no more attention than an ordinary 

 stationary engine. 



A great number of experiments have been 

 made with these three signals. From their 

 average it appears that the power of the first- 

 class siren, the twelve-inch whistle, and the 

 first-class Daboll trumpet may be thus ex- 

 pressed: siren, nine; whistle, seven ; trumpet, 

 four ; and their relative expenditure of fuel is 

 recorded as, siren, nine; whistle, three; trump- 

 et, one. 



The board had in operation on July 1, 1880, 

 fifty-seven fog-signals operated by steam or 

 hot air. 



Bells are also largely used as fog- 

 signals. When the board assumed 

 charge of the establishment, they 

 were rung by clock-work, rude in 

 kind and wasteful of power, its 

 weight constantly descending even 

 during the silent intervals. This 

 detect was remedied, under the sug- 

 gestion of the board, by Mr. Ste- 

 vens, of Boston, who introduced an 

 escapement arrangement, somewhat 

 like that of a clock, and moved by 

 a small weight, the larger one 

 operating only to strike the bell 

 itself. 



The large, unwieldy bell-boats' of 

 the early days of the establishment / 



have mostly gone out of use. / 



The Brown bell-buoy, recently in- 

 vented by the master of one of the 

 lighthouse tenders, is a simple ar- 

 rangement by which the bottom sec- 

 tion of a first-class iron nun-buoy is 

 decked over and fitted with a frame- 

 work of three-inch angle iron, nine 

 feet high, to which a bell is rigidly 

 fixed. Under the bell, which, if of 

 the first-class, weighs 300 pounds, 

 a concentric grooved iron disk of 

 chilled cast iron is fastened to the 

 frame around the disk ; opposite each groove 

 a spring is fastened, and on the disk a heavy 

 iron ball is allowed to roll. The swaying 

 of the buoy, by the undulations of the sea, 

 causes the ball to roll from side to side 

 and to strike the bell with each roll. The 

 VOL. xx. 29 A 



bell to give out the largest volume of sound 

 possible under the circumstances. This signal 

 is never silent, but the heavier the sea the 

 louder is the sound. 



The automatic signal- or whistling-buoy in- 

 vented by Mr. J. M. Oourtenay, of New York, 

 consisted originally of an iron, pear-shaped 

 bulb, say twelve feet in diameter, with a tube, 

 twenty inches across and forty feet long, de- 

 scending through its bottom. The water in 

 this tube acts by its own inertia as a piston to 

 draw in air through an orifice supplied with 

 a retaining valve, and to expel it through a 

 ten-inch whistle. The sound produced is only 

 comparable to itself in kind, and it is of a qual- 

 ity which asserts itself over all others, and of 

 a power audible several miles even against the 

 wind. Its dimensions have been recently large- 

 ly but proportionately reduced without detract- 

 ing from its usefulness. As its action depends 

 on the undulation of the surface, and, as from 

 its great draught it must be moored in deep wa- 

 ter, it is only used in roadsteads or in the open 

 sea. But it has proved so successful that it is 

 used at some points where a light station 

 would otherwise be required, and, in one in- 

 stance, has, satisfactorily to mariners, replaced 

 a light-ship. At the date of its last report, 



COURTENAY AUTOMATIC WHISTLING BUOT. 



July 1, 1880, the board had twenty-five of the 

 whistling-buoys in position. 



The purpose of a light-ship is to do the work 

 of a lighthouse in a place where one is necessary, 

 but where it has not been erected because of 

 the great difficulty, not to say expense, of plac- 



