The news and herald. (Winnsboro, S.C.) 1877-1900, 1879-05-20
SCIENTIFIC.

| Il
thus give us some Glow to tho antiqui-
ty Of our globe. 1t Is therefore worth
noting that Mr., Mellard Rcadc of Liv-
erpo0l has lately contributed to the
Royal Society very suggestive paper,
| In which he endcavors to grapplo with
tho question by employing tho lime
stone rocks of the Garth's crust as an
index of geological timo. Limcstones
have been In course of formation from
tho earliest known geological periods,
but II would appear that tho lator-
formed strata arc more calcarcouS than
the earlier, and that there has, In tact,
been II gradually progressive increase
of calcnrcoua matter. The very cxten.
slvo deposition OF carbonate Of lime
over wide nrenS Of the ocean bottom at
tho present day Ia sufficiently attestcd
by the recent soundiugs Of the Challen-
ger. According to the authors estl-
mate, tho sedlmcntary crust Of the
earth IL nt least one mile In average
actual thickness, Of which probably
| 0nc-tcnth consists of CAlcarCOuS matter.
In seeking tho origin OF this calcaro.
GUS matter, it Is assumed that tho prim-
1.-Two rocks Of tho original crust were of
tho nature Of granite or basultic rocks.
BY tho diSnlcgration OF such rocks,
calcarcous and other scdmcutary de-
posts have been formed. Tho amount
of lime salts in waters which drain dis
trtcts made up Of GRANTEES and basalts
~ found, by comparison OF analyses,
to- be on M average about 1913 parts In
100 900 parts OF water. 1t Is further us.
-umcd that the exposed areas Of igncous
rocks, taking an average throughout
ali geological time, will bear to the cX-
poSurcs OF srIimrntary rocks ratio Of
about one to nine. From these and
other data Mr.. Rcadc concludes that
the elimination OF the calcnrcous mat
ter now found In all tho so,limcntnry
strata must have occupied at least GO0,-
o00 900 OF years. THIS, therefore, rep
rrSrnis he minimum aye of the world.
The nut hor intcra the formation Of the
Lnrcitian. Camuvian and SlIurian
strata mus have occupied about 200,-
0O0 600 OF S,ars; the old red sandstone,
nt carbnuiIcrious, aud tho Doikilitic
Systrms, another 2O0, 900 900; and all
the other strata the rrmnining 20 ,000,-
600. Mr.. RGadc Is, therefore, led to be-
lirvc that geological time has been
enormously in excess OF tho limits
urged hy certain physicists; and that
It has been ample 70 allow for all the
changes which, on the hypothesis of
evolution. have occurred III tho organ
C world.
The following process Of reproducing
linear drawing by tho aid Of photog.
raphy Is said to give excellent results.
Ihc drawings to be copied must bo on
cloth or tracing paper, In order that the
light may pass through It where the
lines do not occur. Under this cloth
or paper the sensitive paper, called pa
per cgon"fcr, il placed, nnd both are ex
posed 10 the light. Under the action Of
The light the irrric salt of the sensitive
paper Is reduced to ferrous salt, which
IA not effected hy the application Of II
solution OF yellow pruSsintc Of potash.
while those portions OF he paper which
have been protected by the lines are
colorcd by the solution. Treating the
paper, therefore, in II prnsSiato bath
brings up tho drawings In clear. dark
blue lines on n white ground. The
sheet of reproduced drawing Is well
washed In water. and then all traces of
the protoSalt Of Iron ia removed in u
'.""'' ""'''"t"tru WIN nyurOrnIOrlG acid,
Color may be applied to tho fac-simile
In tho usual way.
Ihc most certain test CT thc goodness
OF piece of cast iron Is by striking the
euSe WIN hammer. when, II it makes
as'iEht IMPRESSION, denoting some de-
Srrc uI mnlIrnplit!, "a, .fht is vi Il
good quality, provided it br uniform.
II fragments fly of, and no sensible IN
dcntulior hc made, the iron will be
lard and brittle. Tho difference be-
tween good and bad iron Is shown
mainly by the breaking, Good iron
breaks like piece Of good spruce tim
Der bad iron will break like Il carrot,
1t snaps In two.
For tho Joining of belts, good lace
leather, If properly used, being soft and
plinhlo, will always give better salts
faction than any patent fastening or
hooks which have yet beon Invented
In many Instances, the tearing out Of
lace holes ia often unjustly attributed
to poor bolting, when, In reality, the
fault lies In having belt too short and
trying to force 1t together by laciny,
and tho more the leather has been
stretched while being manufactured,
the more liable It Is to hc complained of.
From experiments made upon oak
and other sorts of wood, 1t Is found that
their strength IL proportioncd to their
density and weight; that Of two pieces
Of the same species OF wood, of the same
dimensions, the heavier is generally
the stronger.
Lightning Rrnctlts.
When | boarded tho train ut New
York, Il man said to me:
"Rlg thing this telegraph"
"Nrs,' | said, lit was big rs n crane
vii