New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1857-02-18
INDUSTRIAL AND SCIENTIFIC IN.
TELLTGENCE.

The NEW SCRTw FRIGATBs The SIX new United
States steam iigates, part of which already fin
shed, and the remainder nearly completed, will do
much toward establishing for steam navy reputa-
ton somewhat consistent with American character.
The Minnesota built at Washington has been con-
structed by naval parties alone but the Merimac,
built at Boston, and cruising in the Mediterranean
the Wabash, built at Philadelphia, and now lying
of the Navy Yard at Brooklyn-ths Colorado and
Roanoke, now nearly completed in Virginia, and the
Niagara, at this port all built building,
less under the contract system. The five fntnamed
are heavy war vessels, about 500 tuns each, quite
fully ngged and ordinarily carrying each forty heavy
guns. In fact, judging from the Wabash, the only
specimen which has yet visited our harbor the sppea-
ance Of these ships, wben the huge single suokeppe
is lOwered-which they all enabled to do by an
operation similar to the closing of telescope tubeis
not readily distngushsble from that Of ordinary rst
class sailing frgates. The Niagara ID of different
class In her everything but durability and general
efficiency has been sacrificed to secure speed She is
345 feet in length the longest vessel ever but in
America and may be consldered a ship of 900 tuns
bnrden she carries only twelve guns, and these
are all on the upper deck. Her mssts and rg
ging comparatively light, but nsr boilers and
engines are adapted to the development Of immense
power and great disappointment will be felt should she
fail to be by far the eetest war vessel possessed by
any country. She has four very large boilers, Of the
style patented by Mr.. ID. b. Martip, the present Eng
neern- Chief Of the Navy, each containing six fur
naces. The whole contain FIVE thousand upright
tubes, each three feet long and two inches IN diameter
and mainly through the immensely extended surface Of
these the heat of the fse is economically and rapidly
conveyed to the water TO generate steam. She has
three engines, novel and alnOst unprecedented ar
rangement-the whole object being TO dsvsope great
power without making engines too unwiedy in size.
The Wabash has two engines of precisely the sane
diameter and stroke The Wabash hss two engines of
precisely the diameter and stroke. The diameter
of each cylinder s seventy two inches, the stroke Of
piston three feet Both vessels use steam at pressurs
of about 10 pounds to square inch, and employ It
condensDgly The Niagara cuts off at two-thirds the
stroke; the Wabash, at points variable from 10 to u
inches, from which coupled with the dsproportion in
the number Of cylinders, the relative powers of the
two vessels may be very correctly inferred The Wa
bash we may consider type the four other steamers
the Mernmac, RoaI oks. Colorado and Minpesota-
The propeller Of the Niagara Is of brass, 10 feet
: inches in diameter, and by q complication of
mechanism in the hub the two blades are
each capable of twisting about to assume
positions less obhque ~ as TO vary the pitch
Of the at pleasure but only at - feet pitch are
the surfaces mathemacay parts Of true screw, al
though 1t is designed to be frequently used at great
pitch 80 feet. Tested at dock, she has made 81
revolutions-a very satisfactory performance under the
circumstances. The engines direct acting, hon
zona each being connected to separate crank forged
in the stout shaft. The cylinders are ranged on one
aide Of the vessel ard the condensers, air pumps, &c.
on the other. She has two telescope smoke. piper,
and her guns are all heavy. There are two twelve
inch and ten ten inch guos, al well adapted Tor long
range, or for throwing hollow shot and shek. The
fo'te Of the Niagara viii be dealing with hight swift
enemy, or playing upon heavy and clumsy one at too
great distance to be reached with his guns in return.
The engines Of the Wabash are termed harp engnes,
timar in arrangement to what is known 90 the stesne
engine, but lying horizontal. In general terms the
popularity may be described as consisting m an ooen
or skeleton piston rod, in which the crank has Ibertv
To complete its revolution, mpeled by a coanecsn,
rod extending to its extremity, which 10 supported in
guides as usual Like the Niagara, her engines are
extremely compact and powerful. There four Al
TN boilers, each containing five furnaces. The pro-
peusr Is IL feet inches in diameter with pitch of %
ieet unehangeable. Like the Niagsras her propeller
OF brass, which metal s not affected by sea water
10 ecoromize steam. the engines Of all these fngstee
are made with only about three-eghths OF an inch
clearance or space between the piston and cylinder
eao when al the end of its stroke and in consequence
.inch ingenuity and care is exercised 10 preventing
nsse from the presence Of email quantities Of water
"s cylinder, especially on first starting the engines
'Ns OILY seSoSs difficulty which hes yet been devel