The morning news. [volume] (Savannah, Ga.) 1887-1900, 1897-06-12
EXACT SPEED OF A PROTECTIVE.
A System at Fort Hancock That En-
abIes Great Calculations.


Fort Hancock Correspondence of the Phil
adeiphia Times.
1t is now possible to tell the exact speed
at which projectile moves when it leaves
the interior of one Of the great guns which
help Sandy Hook to frown on the world.
This remarkable fact is brought about
by new instruments never used before
being tried here. Few persons outside
army and naval officers have seen this
latest triumph in the science of gunnery.
Sandy Hook is a place where secrecy fills |
the air. Every man around the govern
ment Notifications wears an air of seem
ingly impenetrabe mystery. Not only is
it the fashion to think before one speaks
here, but it is never safe according to
the government etiquette to breathe I'M
less you are sure that action will not
tell any one in any way even the faintest
idea of what might happen. This is the
reason that the test of the big guns has
not become generally known.
The method is as simple as can be- In
its very simplicity lies it's usefulness and
practically. Compared with the present
test. the old ideas Of the theoretical meas
urement of the velocity of a projectile are
but childs play. Here for the first time
is actually measured, even to the, fraction
tile as it shoots on its way of desrtuc-
ton. 1t is to this very end that the navy
have been working always. An ordnance
officer must have accurate knowledge of
the velocity of { projectile that he may
predict it's range and penetration and de-
termine the accuracy of the gun. 1t is an
absolute necessity that the power of de-
struction of the projectile, as well as the
power of penetration at the point of COM
| pietion of its journey through the air,
| should be known. Without such knowl-
| edge there can be no accurate plan 'of
| firing adopted. because to certain ex-
tent it will be guess work.
| The great trouble has been to get some
practical method to bring about the de-
sired range and obtain for themselves a
| positive knowledge of just what it was
practical for the guns to do. Many per-
| sons had the idea that he Indian Head
proving grounds, so called are those
| where the United States makes it's great
| est ordnance experiments. The truth is
| that Sandy Hook to-day is witnessing the
| greatest tests Of ordnance which have ever
| been attempted by the government. The
| experiment which is described in this ar
| ticle is the chief one at present, and it is
| so interesting in its simplicity that an
| outline of exactly what is done is well
| worth ones while to know.
| When the test takes place, two open
| frames are set 100 feet apart in front OF
4
| forth across these frames, making a
| screen through which the shot must pass.
| The wires in each screen form a com
| plete electric circuit, which includes also
| an electric battery and an electric-mag
| net. The projectile, after leaving the gun,
| flies through the wires in the first screen,
| interrupting the circuit and releasing the
| armature of the magnet. In a space of
| time so small as to be hardly conceivable,
the projectile has covered the distance
| between the two frames and pierced the
| wire in the second, interrupting its cleo
| frical current and releasing the armature
Of its magnet as in the first case.
! The interval between the drops of these
| two armatures represents the time spent
| by the projectile in travelling $50 feet. This
| time is indicated by the chronograph in
| the laboratory near by Wires run from
each screen to the laboratory. which is
| fitted up with batteries and switchboard.
| The armature Of the first electro-magnet
| is on iron rod about three feet long, which
| is suspended vertically. This rod falls
when the hrst screen is pierced The arm
| allure of the second elcctrO-magnet rs
| placed a little below the first, and when
| II Is released 10 acts as a knife and.
striking the side Of the falling rod. makes
/ a slight mark.
The distance from this cut or mark from
the end OF the rod indicates the distance
| through which the rod has dropped while
the projectile is passing from one screen
| 10 another. This forms the unit for the
| calculation Of the projectle's velocity In
| feet per second New explosives and high
| power guns have increased the initial We
| locity Of projectilos wonderfully In the iast
few years. Projectiles may be expelled
now with a force that will make them ef-
fective at a range far beyond ordinary eve
| sight. II Is not generally known that the
! government al present Is paying more at-
tention 10 the fortincations IN ana about
| New York harbor than at any other point
| This Is due 20 the fact. according 10 the
| statement Of an army officer high IN the
| councils OF the nation. that the possibility
| OF trouble with Spain has, IN the govern
| ments eye, developed into a probability
| This being the case the necessity is greater
| than ever for knowing exactly what the
fortihcations of Sandy Hook where Fort
| Hancock is located, amount to. II De- alb
solutely necessary 10 know Just how Gar
away tho gunucrs az the fort can strike
blows that will tell upon the war vessels
/ of an enemy.
AZ prosentit Is the accepted fact that the
/ only Vulnerable spot on the coast line IN
] the vicinity Of New York is Just on Conoy
! Island, for vessel could, On a calm day