SOUND-SIGNALS. 



721 



Skerryvore lighthouses, says he douhts if either 

 bell has been the means of saving a single 

 vessel from wreck during fog, and he does not 

 recall an instance of a vessel reporting that 

 she was warned to put about in the fog, or 

 that she ascertained her position in any respect 

 by hearing the sound of the bell in either place. 

 Gen. Duane, U. S. A., says a bell, whether oper- 

 ated by hand or machinery, can not be consid- 

 ered an efficient fog- signal on the sea- coast. In 

 calm weather it can not be heard half the time 

 at a greater distance than one mile, while in 

 rough weather the noise of the surf will drown 

 its sound to seaward altogether. The use of 

 bells is required, by the International Code, on 

 ships of all nations, at regular intervals during 

 fog. But Turkish ships are allowed to substi- 

 tute the gong or gun, as the use of bells is 

 forbidden to the followers of Mohammed. 



Whistling-Buoys. The whistling-buoy now in 

 use was patented by Mr. J. M. Courtenay, of 

 New York. It consists of an iron, 

 pear-shaped bulb, 12 feet across at 

 its widest part, and floating 12 feet 

 out of water. Inside the bulb is a 

 tube 33 inches across, extending 

 from the top through the bottom 

 to a depth of 32 feet, into water 

 free from wave-motion. The tube 

 is open at its lower end, but pro- 

 jects, air-tight, through the top of 

 the bulb, and is closed with a plate 

 having in it three holes, two for 

 letting the air into the tube, and 

 one between the others for letting 

 the air out to work the ten-inch 

 locomotive whistle with which it is 

 surmounted. These holes are con- 

 nected with three pipes which lead 

 down to near the water -level, 

 where they pass through a dia- 

 phragm which divides the outer 

 cylinder into two parts. The great 

 bulb which buoys up the whole 

 mass rises and falls with the motion 

 of the waves, carrying the tube up 

 and down with it, thus establishing 

 a piston-and-cylinder movement, the 

 water in the tube acting as an im- 

 movable piston, while the tube itself 

 acts as a moving cylinder. Thus the air admitted 

 through valves, as the buoy rises on the wave, 

 into that part of the bulb which is above water, 

 is compressed, and, as the buoy falls with the 

 - wave, it is further compressed and forced 

 through a 2-J-inch pipe which at its apex con- 

 nects with the whistle. The dimensions of 

 the whistling-buoy have recently been much 

 diminished without detracting materially from 

 the volume of sound it produces. It is now 

 made of four sizes. The smallest in our waters 

 has a bulb six feet in diameter, and a tube ten 

 feet in length, and weighs but 2,000 pounds. 

 The largest and oldest whistling-buoy has a 

 12-foot bulb, a tube 32 feet long, and weighs 

 12,000 pounds. 



VOL. xxiu. 46 A 



There are now 34 of these whistling-buoys 

 on the coast of the United States, which have 

 cost, with their appurtenances, about $1,200 

 each. It is a curious fact that, in proportion 

 as theyare useful to the mariner, they are obnox- 

 ious to the house-dweller within ear-shot of 

 them, and that the Lighthouse Board has to 

 weigh the petitions and remonstrances before 

 setting these buoys off inhabited coasts. They 

 can at times be heard 15 miles, and emit an 

 inexpressibly mournful and saddening sound. 



The inspector of the First Lighthouse Dis- 

 trict, Commander Picking, established a series 

 of observations at all the light-stations in the 

 neighborhood of the buoys, giving the time of 

 hearing it, the direction of the wind, and the 

 state of the sea, from which it appears that in 

 January, 1878, one of these buoys was heard 

 every day at a station 1 mile distant, every 

 day but two at one 2 miles distant, 14 times 

 at one 7-J miles distant, and 4 times at one 8 



FIG. 1. COURTENAY' s WHISTLING -BuoT. 



miles distant. It is heard by the pilots of the 

 New York and Boston steamers at a distance 

 of one fifth of a mile to 5 miles, and has been 

 frequently heard at a distance of 9 miles, and 

 even, under specially favorable circumstances, 

 15 miles. 



The whistling-buoy is also used to some ex- 

 tent in British, French, and German waters, 

 with good results. The latest use to which it 

 has been put in this country has been to place 

 it off the shoals of Cape Hatteras, where a 

 light-ship was wanted but could not live, and 

 where it does almost as well as a light-ship 

 would have done. It is well suited for such 

 broken and turbulent waters, as the rougher 

 the sea the louder its sound. 



