Eagle River review. [volume] (Eagle River, Wis.) 1890-1927, 1914-10-09

the bat. The extremely delicate nature Of tha
u"e "insS' tosetner with the senstiveness of
It's sixth sense contained in it's delicate face
nerves enables the bat to Judge the distance of
any OBJECT by the lapse of time between the send
ing out and the receiving of the waves 1t is
this exceptional mechanism and not any faculty
OF seeing In the dark, which enables the bat to
ny unerringly without the least light to guide it.
Thls was proved a. hundred years ago by the Able
Spallanzant who made experiments by blotting
out the eyes Of bats with red hot irons and found
that they got along just as well without eyes
with them. Other experiments without cruelty.
may be made 80 show the same thing.
We all know that If we capture wild bird and
liberate it in a large room with closed windows,
it makes wild and furious rush for what its
senses tell 1t is opening through which it can
escape. Its eyes do not reveal the presence of
the glass, and the result is a broken neck. A
bat liberated under similar circumstances makes
the same dash for freedom. The Tapping of its
wings, however brings its sixth sense into action
and it soon perceyes that it is face to face with
solid wall and stops short before it touches
the glass.
Sir Hiram proposes to apply this sixth sense to
sea-going vessels. His apparatus will produce at
mospheric vibrations Of about the same frequency
as those produced by the bat but Of energy at
least three hundred thousand times great.
These will not be audible, but they will travel
at least twenty miles, so that they could be re-
that distance and would be able to travel at least
five miles and return back to the ship reflected
echo that would be strong enough to be detected.
In describing his invention Sir Hiram states
that it might be considered an artificial ear. The
apparatus is provided with large diaphragm
tightly drawn over a drum-shaped cylinder, and
so arranged that the atmospheric pressure Is al
ways the same on both sides, quite irrespective
of any air blast. It is therefore always able to
yibrate freely in response to the waves OF the
echo and its vibrations made to open and
close certain electrical circuits which ring Sc
res of bells of various sizes. IT, for example, the
object is very small at very great distance
from the ship, very small bell rings, while a
large object at distance of two miles would
ring larger bell and very large object
still larger bell The apparatus gives an audible
notice if anything is ahead of the ship.
Another apparatus, similar to the first, is pro-
vided but instead of ringing bell it produces a
diagram of the disturbances in the air-that is,
when there is no noise except that due to the
action of the ship or the sea waves, a wavy line
is produced on paper, but whenever the vibrations
sent out by the vibrator strike object and re-
turn the wayy line on the paper becomes very
much increased in amplitude, so as to be easily
observed and the distance that the object is from
the ship can be measured by the length of the
paper strip between the giving of Of the vibra-
lions and the receiving of the echo. In this way
the distance of the object can be determined with
a considerable degree Of accuracy, and the size
Of the object may be determined by the amplitude
of the waves that return.
The apparatus for producing the atmospheric
vibrations should be placed well forward on the
main deck or In any other position where it can