The sun. [volume] (New York [N.Y.]) 1833-1916, 1861-02-11
Scientific Items.

Ztsc hs MATERIAL IN BUILDISG.-It ap-
pears from report published In France the use Of
Inc, for purposes OF construction that most Of the
iefects experienced In tho employment Of this
material arise from ignorance to the proper mods
IN which II should bs thus us,d tho ons Inject
70 be kept In view being 70 permit perfect fresdom
10 tho sheets, to conhus them nowhere, and 10
icparsts lsppths Of guttering, and any other por-
lions of roof requiring " be made In long pisces,
" much ~ possible. Ewes CUTTERS should be
made in short lengths, bent In the direction OF the
way In which the sheet has been rolled, and sol.
iered, tho solder being put betwees the sheets
Ind one sheet lspping over the other must they
s screwed 10 the raters' fs,t, al this 10 practice
which OCCASIONS . constant failure In the joints Of
ron cave. CUTTERS Wherever down pIps comes
here should 10 q stopped end In the gutter.
lsd tho gutter should not H. continued longer
lhan possible In ono piece where 1, Is laid behind
! Parspet, separate piece Of flashing will dis-
connect II wholly from tho sheetIng on the roof.
For guttsring, tho gauge used should 10 Increased
m proportion to length there should be proper
lubstanco in all cssor. Olk boarding will spoil
he Elnc, and tho Ar should bs dry---th boards
aid With On aperture Of shout half inch between
I.ch II they are damp, ss much oIila,ion will
kAko place On tue VI hiIo ~ oh sho
bp oft. II Rappcsrs nom sGtual experiment that
me oxidation proceeds for sbout four yssr, grad
uslly diminishing ansr the hrss three montbs,w when
II hsrdeu, into protesting cost OF . dark gray
,olor, preserving the metal beneath from further
deterioration. II app'Ars IN bs evident that .
,hset Of emo exposed TO the atmosphere for series
# years loses little or nothing Of its weight or
lhskn-as, and that its surfsco remains hard and
polished like enamel.
WORKING oF ESGLIsH GRASIrE.-A writer
In the London Builder gives account, of much In
isreht, Of tho working of English grsn'ts in th.
luAria, und ~ the BuheequsDt artistic proc' oi
Recommendation which are Spoiled 70 with 30 msoh
success. ,
Az the quarriss, holes arc drilled, or jumped, a.
II Is called, into the rock; thass arc supped wno
Eunpowu.r and hrCd. and thus the great mAssrs sis
blasssd out which are after~a'ds split into hiceks
with geG Couststiug of steel wedges ant fsathss'
"a they arc called. This blsk In which these ai'
lpssrtsd, Ia partially split, ,hs crack beins started
They aro AtsryysIda fashioned wsh . large nam
mer, called "a muckle, aud pitching TOOL, aud vAIi'
Gus picks points and chtselS. ~ nna SURFACE 10
tsouir,d, IL Is axed. Tha iool with which tho hole
Irs male sonsists long har, thick In tho cen'r
10 hold hy with a Chlstl edge at either end II u
used by being raised and lst fall with = Jumping
motion, whenas its name and being tunnel par
tally siter each blow. thus wins Its way throusi
The Iard.s. rock. Polishing, when required. 4
now ca .ried on extensively by meass t steam
process which, though Tending greatly /" 'nhsnc'
the good appearance of most kin's Of .tIanite- u
rom thshlidnsAs oithe maserisl, necessAdiy 0ossy