Omaha daily bee., 1897-04-24
AID TO NAvIGATIoN.
How the Eophone Locates Sound and
Avoids Danger.

How the Eophone Locates Sound and
Avoids Danger.
When a steam " is plowing its way at sea
or in a harbor in broad daylight and clear
weather, says the New York Herald, the
passengers do not concern themselves about
the difficulties Of navigation. In fact, many
OF them would be inclined to doubt that
there were serious problems to be solved by
| the captain in making his way from wharf
| to wharf or port to port. IL looks so easy
| to run from one place to another and to keer
out of the way of other vessels.
Even at night and in fog travellers do not
think that the situation involves any great
! amount Of anxiety, because they are accus-
toned to making voyages without mishan
or excitement, and they give little heed To
the difficulties that besct the captain, except
perhaps, to bless their landlubberly souls
that they don't have to spend the night ex-
posed to tho fog and wind.
1t is not difficult to avoid another ship II
one knows where she is, and to locate the
exact direction whence sound comes solves
the problem. 1t is the result that has been
attained by an instrument briefly mentioned
in a recent Sunday Herald. The eophone
is a device that enables a man to see with
his ears. That may sound like a Hiber-
nianism, but 1t pretty nearly expresses
the fact.
The instrument consists Of brass box. fiat
at top and bottom and concave on each side.
In the center of each concavity is a project
ing piece of brass shaped like very protu-
berant human ear. In the recess of this ear
is hole leading into a pipe about three
quarters OF an inch in diameter The eophone
is set on top of a pivot, and IL can be swung
all the way around with very trhing effort
rubber tube is secured to each of the
pipes leading from the eophone and these
tubes at their further end are attached-one
on each side-to headpiece, so that when
the operator puts the latter on his head his
ears come opposite the ends of the rubber
tube.
The eophone itself should be placed in such
a position as to command an unbroken out
look ahead and on each side, as far, at least,
as broad on each quarter. In practical use
the operator should be in such place that
he may instantly tell the deck officer the
bearing of any sound he might hear.
If, for instance, whistle should be heard,
the ordinary lookout frequently would not
be able to tell whence the sound came. But
when the sound struck the eophone the oper-
ator would hear it plainly with one ear and
perhaps not at all with the other. Instantly
he would swing the eophone around until he
got the same volume OF sound in each ear
Then the front end of the eophone would be
pointing straight toward the location of the
whistle. Any everyday seaman can deter
mine the bearing of the noise producer in
three seconds, There is nothing requiring
special education in the operator. Any sea-
man with good hearing can work il with
certainty and rapidity.
The arrangement of the headpiece prevents
the operator from being confused by noises
close at hand aboard his own ship. He has
an instrument that greatly augments his
hearing, while it also determines whence a
sound comes. Several times, while expert
menting with the eophone, the operator has
reported hearing distant sound long before
IL was audible to persons on deck.