The news and herald. (Winnsboro, S.C.) 1877-1900, 1879-12-25
SCIENTIFIC,

Paris Astronomical Museum.
cradle progress has been made with tho
new meuseum now forming at tho Paris
Observatory, Among other objects
of historic interest; It will cont ain n
pair of Mcrcator's globss, dating from
the middle of the sixteenth century.-
That figuring the earth is the first on
which mcridians of longitude and par
allels of latitude were laid down. Tho
groat cquat orial lakes Of Africa, it
is reported, are all to be found upon it..
The glass cases contain the first porta-
Die meridian circle constructed on Ad-
miral Mouchez's plan ;the pendulums of
invar3lDle dimension employed by the
Captains Fraissinet and Dueperre in
thelr voyages around tho world, for the
determination of the absolute Yalne of
intensity of the centripetal force and Of
gravity 1T different points Of the earth 8
surface and the apparatus used by NJ.
Cornu, OF the Institute, with view to
determine the velocity Of light from OBJ
servations made between the Obscrva-
tor aud the TOwor Of Montihery.-
Another glass case, adds the journal des
Dc6ats, contains the standard metre of
Tie First Republic the toise used 1888
III feru for measuring degree at the
equator the toise used in Laplaud some
short time afterward for measuring the
poplar degree, and the plantinum kilo-
sralnme made by the Republican Com
mission of Weights and Measures.
Fresnel's len, the first ever graduated, !,
is also deposited in the new muscum,
and the object glass Of t Q great astro-
nolncr Cass siAi, which he used in sue
ces<ivel y determining .Lbe existence Of
Juplter's satellites, Saturn's double
ring, the abnormal hatncss Of Jupitor's
poles, and the vast velocity Of his rota-
tlon, as well as that Of Mars. In
ahother or the cases are to be seen the
doubly refractiny prisms with the hclp
of which Arag0 measured the diameter
OF ths great planets, ,Nept INC excepted.
"A ne,o pigment Photographic PROCESS.
which Is especially adapted to solar en-
largements, is published by the Associ-
at;on Beige de photographic, tho plan
Oelng to dissolve wax in benZine,
charge small quanly of cotton with
the solution, anu apply the latter to a
light piece OF plato glass. After this.
inc plate Is provided with a coating Of
collodlon or yarnish, and immersed i'm
water for thirty minutes. 1t Is then
taken out and laid flat on the table.
where 1T Is coated with q mixture con-
sistlng colored pigment, gelatine and
olchromate OF potassium, which, hay
Ing become firm, the plate is allowed to
dry in the dark. in addition to this.
pigment paper is taken ,sensitised In the
usual manner by dipping in a solution
OF Dlchromate of potassium. placed
upon the collodionlzcd surface of ,he
piate-previously moistcned with water
-rubDe' down In order to obtain per-
ioct adhesion, and tinaIy lett to dry
inc plate Is then exposed in the solar
can era-enlarglng-ap -apparalus-by Al
io"ln& the picture rays to act, through
me plate, upon the film treated with
blchromalc. The Cxposurci Is regulated
ny the nssitance of the photo,Eeter.--
The plate Is subsequently, immersed IN
warm water of trirty degrees, after
which the paper is detached, and tho
picture developed in the usual way, II
j. now nXed, and poice OF hitc gela-
llhc IL hn"ly affixed to the picture by
means Vi the roller; and, when this ha.
become perfectly dry, the picture is
detached.
a Process of Wicket Plating, In the
wet way, without the use OF batteries.
has just Deen devised, and Is said to give
good results. 10 Il dilute solution of
chlorlde of zinc-hvc to ten per CENT
't," H'CnSi sulpHItc IS auuCu 10 lnl-
part decidedly green color to il, and
the solution Is then hcatcd.to boiling in
u porcelain vessel the cloutIing of the
liquid, from separation Of bMsic zinc
salt, is no draw back, us it does not In
teftcre with effectiveness OF the bath -
ihe articles to be nickel coated, being
hrst carefully cleaned Of oxide or
grease, are suspended in the solution
from thirty to sixty minutes, the bath
0eing kept at boiling temperature.
"heh the articles are found to have be-
come uniformly coated, they are re-
moved. washed In water In Which there
Is Il little chalk In solution, then dried.
and finally brought to u polish with
chalk or other suitable material. Bv
euestitution Of cobalt salt in place of
'hc nickel, art icles may be similarly
coated with cobalt.
1T