Great Falls daily tribune., 1919-07-13
ANIME. e-AACAoR, C-Pluht1ET n-Ir1hAERs.oN FEET
N-2FT-DsTANCE NINE SETS OUT OF wATEK~~

These rails lead TO the stern Of the shiy
and end there at port through which tn,
mine Is launched overheard. Two. three
four or more lines Of rails, leading into
the launching ports from switches and
side tracks inside the ship. where the
mines are stored, make 1t possible to
launch mines at the rate OF two or three
minute or even faster II necessary.
The trick that determines the depth be-
low the surface at which the mine will
float once It is anchored safely at the
bottom is turned by adjusting the length
Of the cable to which the plummet is at
tached before the mine is launched. Is It
desired to have the mine float at depth
OF seven feet below the surface, Then
the plummet line Is exactly seven feet
long. and this Is what happens when the
mine. nested in its anchor box. is dropped
overheard -
Water Frees Trigger.
First the entire apparatus starts to sink.
the weight OF the anchor dragging the
buoyant mine below the surface. A few
feet below the surface the water pressure
acts upon trigger. releasing it. and
thereby unfastening the catchi that holds
the mine to the anchor box The mine
rises to the surface. the anchor box con-
tinues to sink. its downward progress now
accelerated. since it is relieved OF the
buoyancy OF the mine But the solid
plummet has reached the end OF its cable
and Is hanging at the same distance below
the anchor that 1t is desired to have the
mine float below the surface,
So long as the weight of the plumm.t 1.
suspended from the anchor box the wind
lass or reel from which the mine cable
Is paid out continues to function and III.
anchor descends. with the mine itself still
floating on the surface The instant the
plummet touches bottom the remov., ~,
'ne strain on the plummet cable releases
a catch inside the anchor box, which locks
the reel and prevents the paying our .,
any more cable.
II the plummet cable Is seven fee. ,o,x
Il Is quite apparent that this locking OF
the reet VIII occur when tho anchor Is
just seven feet from the bottom. Blu. IN.
anchor continues to sink and pull the
mine down with 1t. now that the mine
cable no longer runs freely from the reel
Tho mine itself, therefore. II drawn down
from the surface to depth Of seven feet
Or to such other depth A. may have been
determined in advance by the length of
The cable Of its particular plumnet.
This method Of planting mines. and the
nine anchor mechanism that makes i'll
possible to lay them rapidly and in large
numbers. has been among the most care
'ully guarded Of the navy secrets.
MsvaI Aviatio. work.
Because SO much has been said and !
written about military and naval aviation
he impression prevails that the diriEible
balloon has proved . failure and that
lighter than Air types Of aircraft are OF
10 Importance Quite the contrary il true |
rhe so-called sausage" type Of captive
'alloon is one Of the most important ele-
nents in the observation service Of war
n land. The development by the navy
4 the kite balloon. which at q height of
mile or less Is towed behind a ship. gives
wider range Of observation of the ene-
ay's movements than would be possible In
ny other way. And the dirisible itself.
9th the rigid or Zeppelin and non-rigid
r "Blimp' type. have been highly de-
eloped by the navy.
A very important part OF our Navy
programme for . largerl