ose 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.]

_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 projects, 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 10-inch locomotive whistle with which it is surmounted. These
holes are connected with three pipes which lead down to near the water
level, where they pass through a diaphragm 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 immovable 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 21/2 inch pipe which at its apex connects with the
whistle. The dimens