The fuses shown from left to right are: minor caliber percussion fuse,
minor caliber magazine percussion fuse, major caliber percussion fuse,
major caliber magazine percussion fuse, triple, double and single train
time fuses. The time fuses all contain a percussion element to insure
their exploding on impact if not previously exploded. No special tool is
required for setting these fuses. They are made up to 27 seconds burning
time for guns of 2,600-foot seconds muzzle velocity, and up to 36
seconds for mortars and guns of 1400-foot seconds muzzle velocity.
* * * * *
What is a Deep-Sea Diver’s Dress Like?
There are now two general types of deep-sea diving equipment: an India
rubber dress, covering the entire body, except the head, which is
covered by a helmet, and another apparatus which is constructed entirely
of metal.
The India rubber dress has a neck-piece or breast-plate, fitted with a
segmental screw bayonet joint, to which the head-piece or helmet, the
neck of which has a corresponding screw, can be attached or removed. The
helmet has usually three eye-holes, covered with strong glass, and
protected by guards. Air is supplied by means of a flexible tube which
enters the helmet and communicates with an air pump above. To allow of
the escape of the used air there is sometimes another flexible tube,
which is led from the back part of the helmet to the surface of the
water. But in the more improved forms of the dress, the breathed air
escapes by a valve so constructed as to prevent water from getting in,
though it lets the air out. Leaden weights are attached to the diver,
and his shoes are weighted, that he may be able to descend a ladder,
walk about below, etc.
[Illustration: DIVING-DRESS AND DIVING-HELMET, BY SIEBE, GORMAN & CO.
A. Pipe by which air is supplied.
B. Valve by which it escapes.]
Communication can be carried on with those above by means of a cord
running between the diver and the attendants; or he may converse with
them through a speaking tube or a telephonic apparatus. One form of
diving-dress makes the diver independent of any connection with persons
above the water. It is elastic and hermetically closed. A reservoir
containing highly compressed air is fixed on the diver’s back, which
supplies him with air by a self-regulating apparatus at a pressure
corresponding to his depth. When he wishes to ascend he simply inflates
his dress from the reservoir.
Another form, known as the Fleuss dress, makes the diver also
independent of exterior aid. The helmet contains a supply of compressed
oxygen, and the exhaled breath is passed through a filter in the
breast-piece which deprives it of its carbonic acid, while the nitrogen
goes back into the helmet to be mixed with the oxygen, the supply of
which is under the diver’s own control, and to be successively breathed.
A diver has remained an hour and a half under thirty-five feet of water
in this suit.
A considerable enlargement of the field of deep-sea diving is the result
of the invention recently of a form of diving apparatus which is
unaffected by the limitations hitherto imposed on work of this kind. A
possible depth of 204 feet is recognized by the British Admiralty
regulations under the conditions that obtain with the common form of
diving suit. Yet this depth has probably never been reached. One hundred
feet is the rare descent of the average diver and 150 feet his maximum.
With the new apparatus a submergence of 212 feet has been obtained, and
this might have been indefinitely extended had there been a greater
depth of water at the place where the experiment took place--Long Island
Sound during the latter part of 1914.
The new diving apparatus is constructed entirely of metal, is rigid and
is made of such materials that it is strong enough to resist the great
pressures found in the depths to which it can penetrate. The material
used is an alloy of aluminum, and the diving case weighs complete about
500 pounds. When in the air, the man inclosed in it is incapable of
imparting movement to it, but in the water, which counterbalances the
dead weight of the apparatus, he can easily move the articulated
sections as well as give himself motion through the water. The
articulated portion consists of about fifty turning joints, fitted with
leather packing, which swells and has an increased effectiveness under
increased water pressure. To prevent the pressure-force of the deep sea
from jamming the joints, roller bearings are so arranged about them that
freedom of action is constantly maintained.
The diving case is not absolutely water-tight, nor is it desired that it
should be so, as the slight leakage acts as a lubricant to the joints,
and aids in their movements. The danger arising from the intake of water
thus into the diving case is averted by the action of an ingenious pump
appliance, which serves two purposes: that of pumping the water out and
pumping the air in. The diver in this invention carries his pump with
him and has air supplied to him at atmospheric pressure.
At the back of the diving case is a recess and in it is installed a
compact but powerful pump, which sucks from the feet of the suit all
leakage and forces it at once outward. This pump is worked by compressed
air, and the air, after performing its mechanical part of driving the
pump, is exhausted into the suit for the diver to breathe and then
passes to the surface through the free space in an armored rubber tube,
within which are led down to the diver the compressed air pipe for
driving the pump, and the electrical connections for telephone and lamp.
Thus the diving case receives a thorough ventilation, and it has been
found that should the pump fail to work for a number of minutes there
would still be enough air remaining in the diving case and the tube
space to supply the diver’s needs for at least the length of time he is
being hauled to the surface.
During the experiment in Long Island Sound the pump was stopped for ten
minutes, while the diver was at a depth of 100 feet. He suffered no
inconvenience, and when the compressor again was started he was lowered
to a depth of 212 feet. If such a condition as failure of the pump to
work for ten minutes had arisen during a descent in the old elastic
diving dress the result must necessarily have been fatal. Nor is a delay
necessary in hoisting the diver clad in the new diving apparatus to the
surface. According to the British Admiralty regulations, should a diver
go down to a depth of 204 feet, the time of his ascent must be not less
than one hour and a half. In the Long Island Sound experiments the diver
was hoisted to the surface in eighty-seven seconds. He was totally
unaffected by the abrupt change in pressure, although the deepest he had
ever been was ninety feet, and on that occasion he had suffered from
bleeding at the nose and ears.
Why do We Smile when We are Pleased?
We smile to express our pleasure. When you meet a friend on the street
you smile as you greet him. This is an indication of your pleasure at
seeing him. This is often caused by an unconscious nervous action
produced by the impression the occurrence creates on the brain. You do
not have to think about smiling, but the muscles of your face contract
and give you that pleased look without any effort on your part.
Why do Some of Us have Freckles?
Some people have freckles, when others do not, because all skins are not
alike, just the same as eyes are not all of one color. People with
certain kinds of skin freckle more quickly when the skin is exposed to
the sun. The action of the sun on their skin causes small parts of the
second layer of skin to give out a yellow or yellowish brown substance.
Freckles are most common in persons of fair complexion and hair. In some
cases freckles are permanent, but in most cases they disappear with the
coming of cold weather.