The Minneapolis journal. [volume] (Minneapolis, Minn.) 1888-1939, 1906-02-25


defense mine is fred BY contact, the
observation mine from astation on
shore and the counter.mine, used for de-
stroying other mines and mine fields,
from an electric battery, usually To-
Gated in a launch.
Counter-mires are laid from q boat in
strings Of ten, $50 feet apart, aud when
they are exploded together will clear a
channel Of any obstruction, exploding
any other mines that may have been
planted on the field. The last two
weeks are devoted ito practical work,
which includes planting mine fields and
taking up mines.
Submarine mines are all of heavy
sheet steel, thirty-two inches in dia-
meter, the counter-mines being large
tanks or cylinders, 4S inches high, car
rying a charge of 527 pounds Of gun
cotton. Tho others are round as a ball,
thirty-two inches in diameter and car
rying 1877 pounds of gun cotton.
This charge will throw column of
water Of the size of building 125 feet
long 100 feet in the air and will blow
the bottom out of any battleship.
Counter, mines are common to all navies,
but naval defense mines are used in
this form only by the navy of the
Wonders Of the Torpedo.
AS the most Important, the study of
the torpedo takes the longest time.
When man finishes the course, he
knows all about torpedo, how to take
it apart, assemble it, it's mechanism,
its operation, how to fire and guide it.
And that is great deal, for torpedo
may be regulated and guided until it
will seem to act with intelligence. 1t
can be run at any depth up to twenty
feet and will keep at that depth, altho
it cannot be made (the Whitehead as
used in our navy is referred toy to
| firing it can be started in one direc-
tion, and so adjusted that after running
in that direction fora desired number
of feet, it will turn at right angles and
finally strike an object in an entirely
| different quarter from that for which it
started. And it can be controlled in
other ways almost as surprising.
A Whitehead torpedo is, in one Of the
sizes used by this government, eleven
feet, eight inches long, eighteen inches
in diameter, Of 3-16-inch sheet steel,
and consists Of head, middle body, after
body and tail. One of this size is worth
| pedo station worth $4,000 each.
The smaller ones will run for 1000
yards, the larger for from 1900 to 5000
yards, at high speed. The larger size
| is sixteen feet seven inches in length
and weighs: 8l2 pounds.
The head holds the explosive charge
| The war-head, used only when the tor.
pedo is sent on a real business engage.
ment, is of phosphor bronze, filled with
charge of 1876: pounds fwet guncot
ton, which would rust steel. The exer
else head, used in practice work, is OF
steel andn is filed with water to make
up for the weight Of the service charge
The primer is of dry guncotton an6
weighs a pound and six ounces.
- Learns to Make Explosives.
In the course on explosives the sea
men gunners get "a general knowledge
of the manufacture of guncotton an(
smokeless powder, how it is cared fol
on board ship and where slowed. o.
board ship wet guncotton is slowed il
wet guncotton magazines down low for
ward or aft, the dry primers being
placed up around the decks, above wa
Ter. All guncotton is examined weekly
monthly and quarterly, any loss O.
weight in wet guncotton, which is bat
stuff to handle, being made up by add
ing water. - -: - II
= In the diving stunts the beginne
first puts on suit for diving in eigh
or ten feet of water until he become
accustomed to the sensation of being be
low the surface aThen the depth j
gradually increased tousixty feet. 4
learns to, use the> life line and air hose
the signals and to work below the SUI
face. III. /.