The Whistling Buoy [pp. 605-616]

The Whzistling Buoy.e
est boon to the seafarer. As is well
known, a very moderate amount of fog
or mist is sufficient to obscure the most
powerful light,-even the electric light
being no exception. For instance, on
the night of November 9, I858, the ship
Lucas struck on Saddle Rock, just under
and not three hundred yards from the
South Farallon Light, as powerful a
light as any on the Pacific Coast: and
although burning at its greatest intensity, it was not once seen during that
dreadful night,-not until daylight did
the survivors perceive their whereabouts.
The whistling buoy was invented and
patented in I876, by the Courtenay
Automatic Signal Buoy Company, of
Newvburg, N. Y., and as originally manufactured consisted of a pear-shaped bulb,
made of boiler iron, twelve feet in diameter at the float line, rising out of the
water to a height of thirteen feet, the
bulb surrounding a hollow iron cylinder
thirty-three inches in diameter, extending from the top of the buoy down
through the bottom and into the water
free from wave action. This cylinder is
open from the bottom for a distance of
thirty-two feet, to an air-tight diaphragm
within the bulb; while from the diaphragm to the top plate of the buoy extend three tubes,- two of which, three
and one-half inches in diameter, are
open at the top, with ball valves at their
lower extremities for admitting air into
the buoy; the third tube, two and onehalf inches in diameter, is open through
the diaphragm, and conveys the air out
through a ten-inch locomotive whistle
on top of the buoy.
Its action proceeds upon the theory
that the depth to which water is agitated
by waves is not much greater than the
height of the wave measured from
trough to crest,- that is, a wave ten feet
in height will only agitate the water to
a depth of about ten feet below the surface. Accurately,it has been ascertained
that a wave ten feet high and thirty-two
feet long will agitate the water only six
inches at ten feet below the surface,
while at a depth equal to the length of
the wave the motion is diminished to a
very small fraction. But for all practical
purposes, the depth of motion below the
surface corresponds with the height of
the wave above.
Now with the cylinder of the buoy
reaching into water not affected by the
motion of the waves above, it is very
evident that the water will rise in the
cylinder, not to the height of the waves,
but to the mean average level of the sea,
which would be half the height of the
waves, and remain almost immovable, no
matter how many waves raise and lower
the buoy. So that with the buoy rising
and falling with each wave, we have a
moving cylinder encompassing a fixed
piston of water. As the buoy rises to
the crest of the wave, the space between
the constant water level and the diaphragm is greatly extended, and air is
sucked in through the two large tubes to
fill the space; as the buoy descends
again, the diaphragm descending upon
the water piston, the air is compressed,
and not being able to escape by the three
and one-half inch tubes by which it entered, owing to the ball valves, is forced
out the two and one-half inch tube
through the whistle. Of course the
weight and proportions of the buoy are
calculated to a nicety to conform with
the length of the cylinder, so that the
expansive force of the air shall not exceed the resistance of the column of
water, otherwise the water would be
forced out at the bottom of the cylinder.
Any wave or undulation which will
cause the buoy to rise and fall six inches
or more will sound the whistle; and it
is claimed that the power of a whistle
operated by compressed air, as in the
case of this buoy, is much greater than
if operated by steam of an equal pressure, owing to the fact that the sound is
transmitted in the same medium in
which it originates; while in the case
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[Dec.