Evening star. [volume] (Washington, D.C.) 1854-1972, 1912-07-28
vice to Prevent Collisions at Sea

paper strip. there are about half dozen
spots. Each iceberg within range has
mace its own record. indicating roughly
its size and accurately its distance.
Soon night is on Us again. accompanied
by slight mist that obliterates tie
lights of passing ships. At about O'Clock.
after sending out many blasts 10 port and
starboard and also dead ahead we have
very slight indication that there is some
large object ten miles distant and very
nearly in the direction we are going. We
expect to get a stronger reading I'm q few
minutes, but do not do so. However,
keep on sending out blasts. and at the
end OF an hour the readings are more dis
tinct and the distance IS reduced from ten
miles to seven, showing that the object I'm
question Is evidently ship going I'm the
same direction as ourselves. but at a
lower speed. We come up 10 her and pass
her in short time.
Next We find that there 81 a very large
object or our starboard beam. Our re-
corder shows the distance 10 be over
twelve miles. and still the markings are
quite distinct. What can il be? Reason
tells us that IL il big liner with her inn
mensely large broad side In a position 70
send back 10 US an echo such as We have
Il "A
We continue sending out blasts. and soon
find that the big ship is going in the same
direction ourselves and at a speed ~
fully three miles an hour faster than
own ship is travelling. In short time
she is so far ahead OF us that VIC cannot
receive back an echo.
The day following is very hne and
cloudless: the sun shines down from a
deep blue sky with remarkable inten-
sity. There is practically no wind How
ever, at about midday. the little wave
let's on the surface OF the water show
that the air Is in motion. Currents OF
cold air are descending. spreading
out over the surface OF the water and
producing the little waves that enable
10 located both the descending and as
cending currents.
The warm air produced by the intense
heat of the sun shining on the surface
of the water is constantly rising and it,
place being taken By the colder cir
above. This OF course. produces a
great many conflicting currents OF air
OF different densities, certainly very
favorable for the production OF acoustic
c.ouds: optical.S, the air il clear and
transparent. At . o'clock We send cut
blasts in various directions. and a.
though there is nothing in sight. we re-
ceive responses OF considerable power.
showing Enthusiastically the presenc. Of
invisible acoustic clouds The readings
the paper strip. however. are drawn
out and much longer than the primary
blast. Acoustic clouds rever appear in
foggy weather. they produced BY
many conflicting currents of air. of diff
ferent denSit!eS. the result of bright and
unrestricted sunshine.
a dark and foggy night. We are ap-
preaching the rugged coast OF Ireland.
We work our vibrator constantly. send
ing out strong blasts every few Sec
onds. but We receive no response until
near morning. We know that there is
no danger, as our apparatus shows that
the coast is clear. We keep OH full
speed until We receive some response to
our blasts. The first is Very feeble ana
comes from distance: twenty minutes
later the record is strong and distinct,
and there is more than one record.
Some objects are only three miles dis
tant and of no great size. while others
are indicated fully ten miles distant.
and. from the size and shape Of the rec
ords, must be of great size
1t is the uneven coast of Ireland. with
mountains In the background. The fog
continues dense: but. working our APP
paratus. We are able to skirt the coast.
keeping our distance from the shore,
and have no difficulty in feeling our
way into port.
Returning to realities. Sir Hiram says
that he has already made complete work
ing drawings of the devices that go to
make up his collision-IGeventing appa-
ratus, showing them in the minutest de-
tail. In conclusion, he writes:
The apparatus will work exactly as
described with the devices already de-
signed, but / not going to rest at
this point. / shall shortly produce a
recording instrument with a selective
power that will not receive any vibra-
lions except those due to the echo or
the blast sent out. This will eliminate
all noises due to the ship and the sea,
and produce a Very clean record"