Tensas gazette. [volume] (St. Joseph, La.) 1886-current, 1914-10-30

be turned nom port to starboard. OF course
there would be no use for the apparatus except
In dark stormy or fogsy weather unless It was
to be used In communicating with other ships.
II the sea were perfectly clear the blasts sent
out would be recorded at the very instant Of
their production but no echo would be produced
But II there should happen to be an object Of any
considerable size at . distance greater than
two or three miles the xigzag line on 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 sew
eral times; and then II the result was always tho
same, 1t 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. It might be
30 arranged that one inch Of paper represented
q mile.
To many It will appear din1cult to reveal not
only the presence Of objects at but also their
size. distance and character. by simply sending
out vibrations and receiving echoes. Sir Hiram
assures US, however, that such IN echo properly
received and recorded will not only indicate size
and shape with q fair degree of accuracy. but
direction and distance with great accuracy. It
will distinguish Q ship from an icebers, will show
whether the object IL stationary or moving. and.
II moving the direction and velocity Of such
movement
Let ~ embark in Imagination. on . ship
equipped with Sir Hiram's invention. We are
well out at sea, our ship making 20 miles an ,
hour, and we ind. upon sending out several
blasts. that the echo reaches In 20 seconds.
We infer that, - Il took ten seconds for our VI
brations to reach the object and another ten Sec
onds for the reflected vibrations to return, the
distance 10 slightly over two miles One minute
later send out another blast, but the result II
stronger than before. We change the direc-
ton Of the blast and nnd that the greatest effect
IL produced when the blast IL sent out dead
ahead; also. that the distance between the object
and our ship II being reduced at the rate Of IS
miles IN hour. Inasmuch ~ our ship II making
only 20 miles an hour. It 10 evident that the un-
known object IL q ship making Is miles an hour
and travelling toward 10 slightly to our star.
board
Our next blast shows ~ that the ship II only
. mile distant. and very much to the starboard.
We follow her direction and when she II IN Q
position to present her broadside to N. We nnd
on sending out . blast that the echo 10 very
strong the bells at the receiver Hng violently and
tho recorder makes . large and distinct marking
on the paper strip. The weather has been %
thick that We have not seen the ship, but We
have q fair idea Of her: We know her speed and
the direction In which she II sailing. Later on.
We receive . 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 NJ. We change
our direction % - to sive them . wide berth.
Subsequently We have . new experience We
send out . blast and receive hack IN echo show.
ing that there 10 IN exceptionally large object
very nearly dead ahead Of N. We know Il 10
large because the distance indicated II ten miles
and the record quite distinct. By sending out