New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1864-04-02

cnvied nv the road The advantage gained by tins pan
would be the securing Of natural g. ana puId rocu;re
q constant expenditure Of an amount Of money larger
than would at fret be supposed The use OF sten ~,
oxide and carbonic acid gases which could not DO en-
tirey removed by the beet devised plan CompTessea
air motor would remove all orlectons nos aor
ventilation but 1t would double the cost Oh rahsPoi"
| ton. ..,.o.,
II REQUIRES bnt little foresight predict That this great
metropolis must sooD require such facilities a ether VI
these projects could furnish for reach within com
paratjvely short time The business ccltels OF tc ey'
ris timely attempt 70 prov ide for the futnie ny
er c0Inpanv should be matter OF general cons fatuin
ton and seems proper that the charter shouu aso
embrace the project now proposed so that ateI eao
n surveys aud estimates they may decide Whener ~
carry the class Of passengers requiring RAPID uan"
underground or overhead. .a
MIR. FI,HER thought favorahy Of the plan proposed
By the Chairman; il was feasible to construct tAe o
posed railway between the avenues A.
| Dr. PAVMrLEE could see no serious opJeclloh 10
UNDERGROUND railway, ceriaiEly those above srouau
would he less inconmoded If passengers were Trans
ported in this way. ,.,
Mr. DBPiS said That it would be well to bear in mird
tie fact tnCt tunnel constructed Few years ago
IN London under the river Thames out ~ was ne'ei
used BY vehicles and nobody visited 1t now exccP u
examine the structure. The same result Wouiu I0uo"
in New-YoTk people would not consent 10 r'Ge un III
crourd when they could have the lgbt Of day iho
nest feasible peI 10 lay the rails III INC sL eets.
serious objection, in the mn4s u some MoIi IN rSe
there are 10 interesting engineering doultlcs III tHe
way There has always been banleIing aiter ssnie
thing very difficult, III order t. engIse PaT ~
"
Brnodwpv and we wi then look upon it, a. we have at
the steam fire engines. aud wonder " u had 10. Dee
introduced before. The greatest otJeotlV 70
railways is the Lign fare passenger can De esrieu
for three cents and the companies would Pay far dlV
idend. o, ,,,s
emit had been in tie London Railway iunnclf
| Prof. JOY of Columbia College e'eed tlat ne my
made passage through portion OF ihe rewn! rb
unrel oppeared 10 be amply ventilated Gud lighted ~
every Gf or sixth block there were openings or 'ho
Iinr1oss and ecross O. passengers. .-,--,.,, ,-c.
DR.. PAi1iAEE said the great point 10 DC einc'. ""S
exped!on People C, Md not be cayIird fast er,ugh'
Mr. BAL1IETT suggested thrt This pogt might oe 1T
tanned by The use Of the pneumatic t"ne. ,. o,,;,r
Ills plan had been discussed at pre- lows meti"s
come further obseryatie rs from M ADaANcb ad
Others. decided TO take up tie question AGAIN.
GEOLOGICAL.
Dr. STEVENS Illustrated with the AID OF deg1aHs INC
peculiar movements which have taken pace IA ils CIV
lnphcayal producing the mountain fyatem ron '1e
Atlantic Coast TO McJLeon County Pa Ihe Eshso
Through which the Potomac River passes was par'iVu
Harry noticed Tie coj formation, the Dcyonlan ana
the Uuper ard Lower Silurian systems were pointed
out The same strata OF coal IN the valleys were iouuu
on the tops Of the mOuutns. Faults occurring * va
rious points through which the river Rsed were sho%n
r these oann0 be explained without diagrams Inc
speaker was listened 10 with evident satisfaction
IRON.
The CHAIRMAN in announcing tho selected subject
for discussion stated that Mr. Charles W. ;. Healon
had been invited 10 address them aud be Wond prSua
bly, devote part Of HE remarks 10 the proper use q oh
in building ships WIZ.
Mr. HEkToS after some preliminary remGl ks directed
attention t. the nainie and peouaIites Of Iron Inc
three most Important varieties Cast lron Hammered
Iron, and Rolled OF Bar Iron. A..
Cast iron is a crystalline metal. having comparative
" little tensile strength but presenting great resistance
10 compression. IL Is mndo maleabie In small canits
hy being subjected TO long continued heat Which blends
together its crystals thus rendering tougher qua less
brittle Tie surface Of cast iron Is made moe marc
Il but brittle if it is poured. when melted mo damp
" mods producing what Is called Chilled Cast Iron
y la Hammered and Rolled Iron the crystalline ar
rangement is entirely destroyed ltS material ese0meS
fbrOus and more dense. One variety OF ron made ny
the hammering process is known homOcpnro,s iron
After further remarks the constitution Of IRON the
speaker directed attention 70 - use II he construction
of vessels of war; and examined the erent systems OF
iron armor nov In use Iherc are 80 proGileht sis'
tems-one usinga plato Of great thckLcss, called The
Solid plate system the other using series Of INN
plates called the Lamna;ed systc.n The Onl, reason
why iron is better adapted 10 resist shot or pro
ecc is that it Is more dense not that rgber h
any other material Iron Is not so gc adapted 70 re-
sisting sndden shock as wood IS taking equal "eshts
OF eacl Tor iustance, tn4c plate OF iron oae foot
sauare and one iuch thick weighing about 40 pounds
and piece of timber foot square and Of such Thick
ness, OF rather length 20 TO "esh the same us le n
plte Strike each with hammer having the sane ce
gree Of fOrce the result will be that an ndenietion VIII
be made in the iron plate and there VIII be badge or
projection upon the opposite side proving that the
Ous strength Of the iron not sufficient 10 resist
the force and spread equally .hrosghout TIC prsc
While on the oter haue the wood wil be dented where
the hammer struck bit there VIII DC no corresponding
10 the late Robert L. Stevens OF Hoboken. N J..
doubtless belongs the credit OF proposing aud partly
building The first iror.clad vessel for resisting proeees
Hs plan was not much TO stop the shot 10 change
Us direction by causing II to glance. The herTinac
was built with the design. The sane idea l. car
licd out in the cOnsc,ion Of the tuIrets Of the mofi
tor class Of vessels bui II has been found y experience
that a shot is not altogether Ineffective which strikes
but docs not penetra The armO Ii hes not yet bcen
rroyed that vesses Of this class can make voyage
/ Angular amor has advantage which outweigAs
the disadvantages attending it, For instance. suppose
the hight o. feet 10 De plated and get a angle OF
forty live degrees the surface vii be nine eet tut tins
position Of tic non dCes lot accomplish tho end m
tended. for shot fred from long distance viii fJi
nearly peTpendicuarly on such sETfaoe The French
were tie rst 10 attempt 10 practically resist Tie 'orco
Of shells fred from bOnbs But the Russians tie
first TO naugnrate tie mode Of horizontal snehriDg by
which they destroyed the Turkish Heet IN the Black sea
Tic effect Of this System OF firing had been prognot
Gated by Admiral DGllgren, and The Dcl!grcn gun was
specially adapted 20 this mode Of attack The increased
destructive power Of guns and prcctes has caused
orrcspOndiIg Increase IN the protective armor Tine
question now remaining is whether the snip can bepro
tcctcd without destroying her seeworhness. This
brings Us 10 the examination OF tie best mode Of resist
ing shot.
Ifa body ola given weight and hardness meets another
like IL 0nd having the velocity, the damage IS nu
ual but II II ne like 1t which IL stationary, the
latter will b. most Injured, and Will at the same time
receive the momentum. But If the moving body Is
brought in contact with stationary Of sufficient
hardness having weight much greater to absorb
the momentum the result will be different. II the yc
ocy OF the moving body II low it viii on striking re
bound but il The velocity is Nigh il will be shattered in
pieces ard the resisting body will be broken also, at the
point OF impact Now, suppose the stationary Dody mas
less hardness the moving BODY VIII penetrate IT, but
with constantly decreasing speed because ls mOlOn
is being transmitted 10 the yielding substance. force
capable Of producing fracture may bo transmitted
through hard substance 10 soft but moi through
& soft 10 hard substance, II apply this principle
10 the armor Of ship shall see that the most ei
Gent mode Of resistance would be not 70 place on out
side Of WOOD but 10 this position Ilis pinc
pie had been tested ct the request OF The speaker b. tie
Department at Washington, and was sooR ni.er sub