The Washington times., 1921-02-20

r row does bat flying through the cir
RI at lightning spsed manage never 10
= hit anythinsf
When the bat darts straight q POUR head
AMI turns suddenly before he celiidss with
You, is it because his eyes guide his move.
ments?
Is it because he smells the obstacle
ahead OF him!
Is it because air waves come back IRON
the object he approaches 10 warn himi
The mystery Of the dartins flight Of bats
in the darkness OF church beifry Or
stygian cave has always pussled science
Has the bat q "stxth senss''f
Does the bat possess some SOFT d spss
sciai. unique and hitherto unHnown sense
by which the little creatures can tell what
is in front of him in the darkness In time
to avoid collision with it?
The bat has interested science for many
years. Many experiments have been mads
to try and find out his secret. Bats have
been turned loose In the laboratories and
examined under all sorts OF conditions.
Fine threads have been stretched across in
haphazard ways in the room, and yet the
bat in its fight. darting here and there. has
been able to avoid running into the threads.
How can a bat, flying at top speed in
room, know that there is fine SIN thread
just ahead of him and turn I'm time TO
avoid It?
Science has at last unraveled the secret.
The true explanation is that the bat
emits tiny sound.waves too high to be aud.
ible I'd human ears, which send back an
echo from all solid objects near to it. The
bat has peculiarly attuned ears, provided
with many external facial appendages that
receive these echoes. The net result is
that the bat receives a sound picture OF
surrounding objects-in other words, it
"sees" with its ears.
Professor Hamilton Hartridse, OF Cam
bridge University. England. Was one or the
group of scientists that solved the bats
secret Professor Hartridse patiently
studied the habits OF bats, which on Sum.
mer evenings few in hundreds through the
windows of the ancient university build.
ing in which he lived. The rooms had been
fitted with electricity, which, OF course,
could be turned OF In an instant
When Professor Hartridge turned the
lights of he found that the bats never
few against the globes, .electroliers or
other fittings, even when there was q reg.
Ular stream OF them passing. rapidly
through the room. As rule they were
flying in flock In one direction.
Then the professor stretched threads
across the darkened rooms, but the bats
always lodged them with unerrins Ger.
fafufy Ha taatod than IA MANY nthor
ways Further, the creatures could always
tell whether a door was shut or opened
wide or Just sufficiently open 10 allow
them to pass. 60 .ssn :
Another observer, Professor A. whitaker.
working IN cooperation with Hhrtridse,
discovered that even when the bats eyes
were covered with wax II could avoid oh
stacles placed in the room, such a. threads
or dozen chairs placed irregulariy The
bats did not so much :. .e.sn these Oh
stacles with the tips Of their wings.
The scientists also noted that bats never
dashed themselves uselessly against win
dow panes, a. many birds DO. This showed
that their peculiar sense told them that
the invisible glass was In their way.
Thus II was demonstrated that the bats
powers we're not due 10 keen eyesight, for
they could "see' IN absolute darkness
their eyes we're only partially developed
and they could see" with eyes covered
II was demonstrated that the power was
not due 10 keenness OF touch, because they
never touched objects.