Bells.—­Bells are in use at every United States lightstation, and at many they are run by machinery actuated by clock-work, made by Mr. Stevens, of Boston, who, at the suggestion of the Lighthouse Board, has introduced an escapement arrangement moved by a small weight, while a larger weight operates the machinery which strikes the bell.  These bells weigh from 300 to 3,000 pounds.  There are about 125 in use on the coasts of the United States.  Experiments made by the engineers of the French Lighthouse Establishment, in 1861-62, showed that the range of bell-sounds can be increased with the rapidity of the bell-strokes, and that the relative distances for 15, 25, and 60 bell-strokes a minute were in the ratio of 1, 1-14/100, and 1-29/100.  The French also, with a hemispherical iron reflector backed with Portland cement, increased the bell range in the ratio of 147 to 100 over a horizontal arc of 60 deg., beyond which its effect gradually diminished.  The actual effective range of the bell sound, whatever the bell size, is comparatively short, and, like the gong, it is used only where it needs to be heard for short distances.  Mr. Cunningham, Secretary of the Scottish Lighthouse Establishment, in a paper on fog signals, read in February, 1863, says the bell at Howth, weighing 21/4 tons, struck four times a minute by a 60 pound hammer falling ten inches, has been heard only one mile to windward against a light breeze during fog; and that a similar bell at Kingston, struck eight times a minute, had been so heard three miles away as to enable the steamer to make her harbor from that distance.  Mr. Beaseley, C.E., in a lecture on coast-fog signals, May 24, 1872, speaks of these bells as unusually large, saying that they and the one at Ballycottin are the largest on their coasts, the only others which compare with them being those at Stark Point and South Stack, which weigh 313/4 cwt. and 411/2 cwt. respectively.  Cunningham, speaking of the fog-bells at Bell Rock and Skerryvore lighthouses, says he doubts 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 operated by hand or machinery, cannot be considered an efficient fog signal on the sea-coast.  In calm weather it cannot 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 substitute the gong or gun, as the use of bells is forbidden to the followers of Mohammed.

[Illustration:  Fig. 1.—­COURTENAY’S whistling buoy.]