The workingman's advocate. [volume] (Chicago [Ill.]) 1864-1877, 1873-10-11
SCIENTIFIC AND MECHANICAL

RESTORATION OF o. PAINTINGS 1t ap-
pears that the brilliancy oi the colors in
oil paintings is due to the optical proper
ties of the substance, contained in the oil,
known as linoline. BY exposure to the
air this substance, at first liquid, absorbs
oxygen, becomes solid and transparent,
firmly enclosing the particles of color.
Linseed oil contains 81 per cent. of this
lInoline By lapse Of time and physical
and chemical changes, the linoline loses III
some degree its transparency and the PIC
ture fades, those colors containing the least
oil changing most Pettenkofer has dis
covered that the vapor Of alcohol will re
new the qualities Of the linoline, al Il he
restores old oil paintings by placing them
over tight box, i'll the bottom of which is
flannel cloth. which has been dampened
with alcohol Of 30 per cent. strength. The
arrangement should be such that every
part Of the picture will be exposed to the
alcoholic vapor.
Passing through the coal region Of
Pennsylvania, not long ago, We saw smoke
issuing from mountain in the distance,
which, we are told, had been burning for
more than quarter of a century and
that great deal of money had been ex-
pended in the attempt to sever the coal
vein and conduct water into the seams To
extinguish the fire, but without success. -
Eds Scientific american
The military telegraph line from San
Diego to Prescott and Tucson, Arizona. is
being pushed forward vigorously under
the direction Of the Quartermaster and
George :. Ladd, cont ractor. A distance
Of twenty miles south of San Diego has
been completed The party commenced
work last week south Of Prescott. There
are material and equipment for $50 niles
Of line on the ground.
PACING ORANGES AND Lemons.
! full-grown orange tree yields from 500 to
/ 1000 fruit annually, and arrives at the
bearing state in three OF five years, as does
the lemon tree both grow luxuriantly in
most soils. The plantations lin the Med
terranean countries) are called gardens
and vary in size, the smallest containing
only a small number of trees, and the
largest many thousands. The fruit is gath
cred in baskets similar to peach baskets,
/ lined with canvas, the basket being held
\ by strap attached and passed around the
neck or shoulders. From the garden, the
\ fruit goes to the repacking magazine, where
it is removed from the boxes III which it
was packed in the gardens, and repacked
/ for shipment by experienced female pack
ers, after having been carefully assorted
/ by women, and wrapped in separate papers
| by young girls. AS many as 500 persons
/ (mostly women and children are employed
by some Of the fruit growers i'll their gar
dens and magazines, III gathering, sorting,
and repacking for shipment, the wages
paid them varying from nine to sixteen
cents day In sorting, every fruit that
wants stem is rejected. The boxes are
then securely covered, strapped and
marked with the brand Of the grower,
when they are ready for shipment. Twenty
years ago, this trade was nothing in its
commercial characteristics, or the induce
ments it offered to capitalists. Now it is
progressing with giant strides into promi-
nence, and Is considerable source Of rev
enue to the government.
BURNING Coal BEDs-The so-called
burning mountain, at Dudweiler, in the
district of Saarbruck, which has been an
object Of interest to tourists and men OF
science for more than a century, is now
shorn OF its attractions to the former il
presents the spectacle of what is, at best
but smoking mountain to the latter il
is mere impOstor, since, instead of being
as was supposed by earlier scientific OBJ
servers, display of volcanic action, or I
proof OF central fires, it is now clearly es
tablished as the result of the spontaneous
combustion Of stratum Of coal These
smoldering fires produced by some change
which takes place in the constituents Of the
coal may, indeed, burn with more or lesl
intensity for centuries. The thought d
such waste is peculiarly distressing at the
present time, and the burning mountain Of
Dudweiler shows only common good feel
ing by mitigating its destructive proceed
ings at this crisis. A coal red at Nieder
planitz, near Zwickau, in Saxony, ha,
been burning in similar manner betweeI
800 and 400 years. The heat given out BY
this subterranean hre, at cost which it il
distressing to calculate, is not wholly
wasted. An ingenious person, since dead
has established magnificent nursery
ground ON the burning area, in which, b.
means of a system Of pipes, the supply q
calorie y regulated and applied ~ viii
Tfopl<A plants ilourish here i'm the opeI
ar WITH a4axuriAnce which the best forcin,
housss and eonservatories cannot insure. :
1<sassg JcsrAdl