The times. [volume] (Washington [D.C.]) 1897-1901, 1900-07-30
THE SUBMARINE BOAT.
SingularIy Silent Foe, But BAL
looms May Detect It.

| NrFOm the LONDON MALI
Experiments made in good light and on
smooth sea have resulted in fixing the
distance at which the submarine, running
on the surface, would become visible at
about seventeen hundred yards. To be or
the safe side ii has been decided in prac,
tieo to make 1t one mile. This is. there
! fore. described as the maximum range of
visibility
1t is thus obvious that beyond a dis
lance of one mile the submarine can navl-
gate on the surface of the water without
fear of being discovered: TO approach any
nearer it must sink below the waves to
/ ensure safety.
But should it happen that in sinking
the submarine is detected fTvia its course
the compass would not show tne deviation.
providing the vessel kept parallel to the
course decided upon. Therefore some time
before arriving at the distance decided
upon as the best for launching the torpedo
(270 yardsl, the submarine will come rapid
ly to the surface, verify or correct its po-
| sition, and then. again submerging Itself,
| it will move up to within go yards OF its
object, launch the torpedo, and hastily re-
| tire. not coming to the surface again until
! quite a mile away.
| The one weak point In this maneuvre is
the return to the surface at a distance Of
| four or five hundred yards, that Is TO say,
within the radius of visibility. II the sea
/ was very calm the optical tube, or coming
! tower, could be employed up to within 500
( yards. At that distance, however, the tube
would begin to be visible to fuose on board
the object OF attack.
more interesting case presents itself
in an attack on moving obieet-for ex-
ample, a war vessel maneuYring in the
open or changing its position in squad
ron. Then we have an exhibition OF some
what more complicated tactics
The submarine must first of all estimate
the speed Of the moving object. Calculat-
ing upon this basis, it will take course
which will enable it to intersect that of
the warship at a given point. That is a
very common problem in navigation and in
artillery work. and one that causes a
sailor little trouble. Difficulty however
may arise by the warship modifying its
course or its speed while the submarine
is submerged Therefore, besides coming
to the surface at the usual distance Of 500
yards, the submarine viii have to repeat
the maneuvre at go yards just before
launching the torpedo.
One curious fact must be noted in fixing
the military value OF the submarine. It
has been asked, while admitting the in
visibility of the submarine during naval
operations, whether it is not possible TO be
otherwise advised of its appTJach and
avoid attack. AS is well known, all battle
ships are furnished with microphones
which receive the sound If the waves and
notify, especially in the night time or lur-
ing fog, the presence and approach Of
other vessels. However, while at a oonsid-
cradle distance the approach of ships OF
even small tonnage is notified by the mi
crophone. this apparatus remains mute as
far as the submarine is concerned. The ex-
PLANTATION OF this fact is TO be found in
the absence of oscillation from the sub
marines electric. motor, the motion of
which is continuous rotation and not the
spasmodic Jerk of the ordinary piston
which so much affects the microphoue
1t has. however. been remarked that
while from the bridge of a ship a sub
merged object can be discovered when it
is quite near the surface of the water. if
observations are taken from n greater
height the depth at which an object may
be perceived is greatly increased. 1t is. !
therefore probable that the progress of /
aercstatfcs will before long have con- 4
siderable effect in modifying the invisi- |
biiity of the submarine. Experiments
made by means OF captive balloons
attached TO warships have established the
important fact that at height of 800 or SEQ Z
yards submerged objects can be seen at a
depth of from 80 to 20 yards and at 4
radius Of more than 200 yards around the
balloon. The higher the balloon goes the
wider becomes the range of observation,
and naturally the greater the security of
the aeronaut. II has been thought OF add
ing to the equipment on every war vessel
a balloon for the purpose of keeping
watch in the depths of the surrounding
sea- and it may well be believed that If
aerial nayif alton becomes practical real
ity it vii. prove to be the most formidable
adversary CT the submarine. This is
possibility which requires to be noted
At a distance of from seventy-ive to
eighty-fivo yards from the object of attack
the explosion of the torpedo is quite harm
less to the submarine and its crew. On ac,
count. however of the great elasticity OF
water. which is an admirable conductor
II sound, the noise of the explosion is
ieard in the submarine and sometimes
;auses the crew to experience temporary
deafness.