New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1895-12-29
MORTARS FOR COAST DEFENCE.
TO BE MOUNTED NEAR THIS CITY, WASH
INGTON. BOSTON, NARRAGANSETT BAY
PORTLAND, CHARLESTON. HAMP-
TON ROADS AND SAN FRANCISCO.

The necessity for better protection for the harbor
of New York than that which Is now AFFORDED by
the forts located the Narrows is apparent TO IN"
most superficial observer. provided he has any
knowledge at all of what a modern man-of-war can
do in the way of fighting at distance This was
remark made by of the older officers of the
Navy yesterday. when speaking of the Venezuelan
question.
AS a part of the coast-defencs system planned in
1Sss-to which attention given few days ago
by General Nelson A. Miles. the commanding gen
eral of the Army--the Government decided TO use
what are officially termed "twelve-inch, breech-
loading, rifed mortars cast iron body steel-hooped
AK TONS The plans called for 632 OF these weapons
and about a hundred have been completed They
are designed to be mounted at New-York CITY
Washington. Boston. Narragansett Bay. Portland.
Me; Charleston S. c.; Hampton Roads and San
Francisco The battery al Plum Island in Graves
end Bay will be completed first, and 1t is probable
that similar battery will be mounted at Fort Wads-
worth. on Staten Island. Another probable site for
a like battery is Davids Island, near New-Rochele.
in Long Island Sound. In service the mortars VIII
be separated into batteries of sixteen each battery
consisting Of four groups of four mortars Each
group will occupy a separate pit. and the whole
battery will be protected by high earihen embank-
ments. A battery of sixteen mortars can be re-
loaded and the fire repeated every few minutes ana
as each harbor is to have several of these batteries
an approaching fleet can be met by perfect deluge
of shot and shell.
bore and is used for throwing she's at high angles
in order TO reach objects 10y their vertical hTe. An
officer of the Army, who has had to do with the
manufacture of these mortars, said yesterday:
The manufacture of these mortars is of much IN
teres as they constitute the highest type OF heavy
cast-ron ordnance ever constructed. Thev Glossy
resemble the steel breech-loading rifles, except
In general dimensions The length of the rifle Is
about thirty times the diameter of the bore. While
that OF the mortar Is only ten 10 one. The mortal
is I29 inches Ions. 3l1 inches in diameter and has
a Pinch bore, but this cast-iron body has Its
diameter increased 10 42l2 inches with steel hoops
which shrun.i the body in two rows. The
process of machining this ordnance. from the cast
ing of the body TO the fitting of the breechblock' IS
interesting but don't need TO go into that for II
would fl column. more of The Tribune The
eleven steel hoops about -hundI edths OF an
inch smaller in diameter than the casting ana
absolutely tight. The rifng process IS intricate
and full Of uncertainty for the results OF labor ana
expense OF months may be entirely spoiled by the
slightest mistake in the growing. There are. how
ever, mechanical contrivances connected WIN inc
detail gets out of alignment There are sixty-eight
grooves cut. each beng 0.3IS of an inch WIDE ana
Sreee nSh to a he uzz an several cuts are taken in
each groove until the ma. one Is barely more thdn
srTape T.. mounted on . carria0s ., un,ous
dess ara rs eG or less Sy ms of spng The
recoil from the firing is checked by piston acting
nicely nh that aer is locked is as firm as
II 1t were a part Of the casting. While loading the
gun is in a horizontal position The shell or hols
low steel shot containing about thirty pounds or
powder, is cigac-shaped and its front end is turned
to an ognal curve. thus Offering the least resist
snce to the air soft-metal collar on the rear end
OF the proiectie is forced into the rifing grooves.
and this gives the shell the required rotary motion.
After the shell has been pushed into the shot
chamber eighty pounds Of prisnatic powder in t.,
serted the muzzle elevated. and then the gun Is
ready to be fired The usefulness OF these mortars
is not question Of theory. for experiments have so
proved their accuracy of fire that seven shots out
of every ten can be landed on a target representing
the deck Of a modern man-of-war.