New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1863-03-13

and criticism, results in improvement even upon the
most successful. Iron aud steel now form part Of
almost every structure devised by human ingenuity
or constructed by engineers.
Heat Is the great source Of power and motion.
We are its slaves without knowledge Of lite effects,
and its masters If we know how to harness it to our
cbario.s when it enables us To outstrp the swiites
race.horse, and transports our heaviest burden' OF
freight aeroes the stormy sea- in spite OF WINDS OF
waves.
If track is to be laid for railroad, slight space
between the end of the rails 10 left for the expansion
aud contraction by changes Of temperature else '"o
rail would be thrown out Of ito position w 'hoiea''
Of temperature, or tom asander when the wea'"e'
was cod and tiis with no greater change thali we
have from night to day, shade or sunshine, sun
mer or Winter. in the temperate zone. The MehSi
tubular iron bridge, and the great Victoria brldse
over the 81. La ~rence would destroy themselves
were II no. for provision made for expansion and
contraction by placing one end Of each span on "''
ton rollers, to allow for atmosphere onshes''
Architects, in designing iron buildings proV'de i0f
llis well known effect Of changes OF temperature
But we need not look 20 these grander efforts Of con-
struc,ive genius for examples. The globes and !
chimneys upon our lamps are broken when une-
ouslv heated: and we cann0tpour hot water into "A !
common tsubler without seeing gu exhibition OF the
Effects of best for the glaze VIII he broken from Tie
ssme causes How it wss possible that this mpor.
tsp effect Of heat upon guns subjected, Oh their in.
terror surface, 10 the most sudden and extreme
changes Of temperature Of which we have any ex.
amples, could have been overlooked by ordnance
officer. j, sufficiently astonishing. II We suppose
diem 10 be competent 10 ill the positions they oc-
cupy. If we grant that their education guarantees
lhe required knowledge, we must conclude that they
40 not do heir whole duty. If they are not compe
tent they are open TO the grave charge Of refusing
TO take cognzauce of suggestions and measures per-
rciins great guns and other means Of national de-
fense, which have been thrust upon their notice by
outside inventors but have been coldly and con.
temptuous'y rejected.
There is no other reason why our haIbors are not
well protected than the doubt that has been on every
necessary bas never been withheld bu, O trustwor.
thy plan has never been suggested
If tie harbor OF New-York is ever assailed by
France or England il viii be with feet of iron-
clad ships npenetabe TO the shot or shell from our
present guns To resist the entrance OF angle ship
Of the warrior class effsctnsy not less than three
rams would be required, and the rams should havo
the qusties Of great speed and great mAneavering
facilities. II tue ron.clad Of the enemy were able
to piesent her bow TO a ram at all times when re-
sistiDg an attack, two other would be reqered
10 insure ability to strike the enemy 10 her SIDE the
vulnerable part to rams. Rams must also have
the qualities Of impenetrable armor and heavy guns
capable Of throwing sbo, at high velocities.
If The wsnios were accompanied by one or two
rams Of ike description, too much would depend
upon contingencies if we hadonly rams.
The Warrior is likely 70 be accompanied, how
ever, by feet made up of iIon.olads, aud rams
with guns.
We could not protect this bsrbor efiectuay with
less than 80 rams, each with and guns sRsus,
what may come against us. Floating batteries may
be sunk by the rams Of the enemy and consequently
we cannot look TO them for protection: and both
rams and floating batteries may be taken by sur.
prise, for ali enemy may not give ne notice Of their
approach. II an enemy attempts TO land and ap.
proach the city IN tho rear, VIC can oppose them
with greater force, by bringing into roQusition
toegraphs, rail Dads, and steamboats, for transports
Ii with wooden, or sbipe without amor, gups
made upon some Of the plans have proposed made
with knowledge Of The effects Of heat upon she me.
tails, moantedn present Notifications, would be
sufficient means Of defenss, sssisted by rams. Bu,
in care of In attack ny jet of iron.clad shps We
must have revolving forts, in sufficient number, |
placed in the center Of the channel % that the On.
envy must pass within short range, and be subjected
10 number Of rounds from each aud IN these tur.
rets We must have guns that will sasly drive sho.
through, or crush in whole side VI any ship carry
ing even the heaviest srmor or plates with which
will Goat. TIE turret must BE- Of such thickness |
that il will retsl the shot from any gun Whatever
and this possible if We conne ourselves TO turets
Of small diameter, and RESI- them on rock founda.
ton. We must have DO open ports through
v nich the ebeays shot can enter. We must
protect the foundation Of the structure from
u o assault by rams, and sufficient number Of
he forts must be provided 10 assault = whole feet
al once as they pass The Is inch RodmsD
quo would be utterly useless in such trrets Of
revolving forts, as there is space about the guns
through which the enemys shot can enter, and e.
whenever a charge 10 fired from Sbem, that gives
more than 800 feet per secondyeocty the guns will
burst Up 70 This time we have only fred 40 pounds
OF cake powder from them, equal 70 about IL pounds
Of quick burning powder, aud they have not been
fired with tha. rapid succession of discharges u
must sometimes occur.in actual shock Of battle Even
that charge 10 80 u,gntcsut for $50 pounds Of hol
low shot, that II would not penetrate three inches Of
solid plate, with wooden backing. Capt. Dahl.
greps rePor, Of Dee, 1862 says, that the utmost Of.
fort Of the ll-lncb guns IN The Monitor had no effect
on the plates Of the Merrimac, and these arc the