Polk County news-gazette. (Benton, Tenn.) 190?-191?, 1914-10-08

be turned from port to starboard. OF course,
there would be no use for the apparatus except
in dark stormy or foggy weather unless it was
to be used in communicating with other ships
If the sea perfectly clear the blasts sent
out would be recorded at the very instant of
their production, but no echo would be produced
But if there should happen to be an object of any
considerable size at a distance no greater than
two or three miles the zigzag line the paper
would be changed, the amplitude of the waves
would be greater and would be very noticeable.
To make sure, the blasts could be repeated
era times; and then if the result was always the
same, it would indicate the presence of some OBJ
ject, and the length of paper between the primary
blast and the echo would indicate the distance
that the object was from the ship. 1t might be
arranged that one inch of paper represented
a mile.
To many it will appear difficult to reveal not
only the presence of objects at sea, but also their
size, distance and character, by simply sending
out vibrations and receiving echoes. Sir Hiram
assures US, however, that such an echo properly
received and recorded will not only indicate size
and shape with fair degree of accuracy, but
direction and distance with great accuracy 1t
will distinguish a ship from an iceberg, will show
whether the object is stationary or moving, and,
if moving the direction and velocity of such
movement.
Let us embark, in imagination a ship
equipped with Sir Hiram's invention We are
we'll out at sea, our ship making 20 miles an
hour, and find upon sending out several
blasts that the echo reaches US in 20 seconds
We infer that, II took ten seconds for our vi
brations to reach the object and another ten sec
onds for the reflected vibrations to return, the
distance is slightly, over two miles. One minute
later we send out another blast, but the result is
no stronger than before we change the drec-
ton of the blast and find that the greatest effect
is produced when the blast is sent out dead
ahead also, that the distance between the object
and our ship is being reduced at the rate of 35
miles an hour. Inasmuch as ship is making
only 20 miles an hour, it is evident that the I'M
known object is ship making Is miles an hour
and travelling toward slightly to our star
board
Our next blast shows us that the ship is only
a mile distant and very much to the starboard.
We follow her direction and when she is in a
position to present her broadside to us, find
on sending out a blast that the echo is very
strong the bells at the receiver ring violently and
the recorder makes a large and distinct marking
on the paper strip. The weather has been so
thick that we have not seen the ship, but
have a fair idea of her; we know her speed and
the direction in which she is sailing Later on,
we receive a series of records from each blast,
showing that there are several small objects in
our vicinity, probably fishing boats. We are able
TO locate them and measure their distance, and
II any of them are dead ahead of us, we change
our direction so as to give them wide berth.
Subsequently we have new experience We
send out blast and receive back an echo show
ing that there is an exceptionally large object
very nearly dead ahead of us We know II is
large because the distance indicated is ten miles
and the record quite distinct BY sending out