Deseret evening news. [volume] (Great Salt Lake City [Utah]) 1867-1920, 1907-07-06
f-v---------1--7 $3.50
SCIENTIFIC MISCELLANY.

bustion OF coal In London discharges at
least half a million tons Of sulphuric
acid into the air each year, and the
effect upon certain building stones is
disastrous. The acid washed down by
rains attacks the lime of marbles, lime
stones and calcareous sandstoneL form-
ing gypsum and causing the surface 10
swell and crumble. a treatment for the
decaying stonework Is the duplication OF
solution OF haryta, which forms an Inv
soluble sulphate with the gypsr@-, ano
liberates lime. which the carbonic ACID
of the air converts into the original
binding cement Of the stone. Referring
to an experience M the Chapter House
at Westminster. Prof A. H. Church
states that carving so soft as to be
brought away by the finger was made
sound and harder that the newly quar-
ried stone.
The adVanta ges of the magnetic cleo
trode lamp over the carbon arc AS
pointed out by c. e. Little. are longer
life. higher efficiency and pure white
instead of mixed blue and white light.
The negative electrode, from which tho
lamp is inaccurately named, Is really
a mixture of three metallic oxides. each
serving a distinct part in forming this
novel and promising source af illumln-
alton. The titaniuln Divide renders the
are luminous. the oxide of iron gives
conductivity when cold, and the oxide
of chromium prevents too rapid con-
sumption.
The transmission of photographs by
telegraph has reached the stage OF
practical results. and actual seeing by
wire is expected to follow soon. korn
reproduces photographs at distance
through the varying electrical resist
ance of selenium, the changing current
registering the lights and shades or
successive points in proper place on a
sensitive plate at the receiving end.
The telssterograph of Berlin, of Nan
cy, transmits photographs by a differ
ent and purely mechanical means, no
selenium being used; while the tele-
graphoscope of the same inventor Is de-
signed to produce an Image of any IL
Illuminated object or scene at any DIS
lance 1t Is believed that the problem
of really seeing by telegraph VIII be
solved by making the Images to appear
in more rapid succession than the ret
ina can separate them. At present the
sending apparatus comprises cam
era obscura with lens and mirror to
reflect the optical image upon row
of so tiny selenium cells, and col
lector for successfully inserting these
cells in circuit. The receiving station
embraces highly sensitive galvano-
meter with three local circuits. the
principal circuit contains the equilibra-
tor and telegraph relay, the primary
circuit OF a small induction coil has in
turn the second part of the equilibra-
tor, and the secondary circuit of the
coil has n gap whose spark controlled
by the distributing collector, perforates
paper with very fine holes equally
spaced between centers but OF size
varying to correspond with points on
the image. This gives a picture re-
sembling autotypy. The equilibrator
the chief part, provides local cur
rent of sufficient intensity TO register
decidedly every change in the feeble
current from the selenium cells.
To give the greatest possible pre-
cision to our knowledge of the atomic
weights OF the elements, an interna-
tional commission corrects the list
each year In accordance with the most
recent discoveries. OF the ~ elements
In the latest list, hydrogen is still the
highest with AN atomic weight of Los.
The automic weight OF oxygen Is l6;
gold 1877 3; radum, 225; and uranium,
the heaviest substance, 23S. b; while
mercury, thelllum, lead, bismuth and
thorium are all heavier than gold.
The compressed air spray has been
used for a considerable time for paint
or. and for whitewashlng tunnels. The
newer art of decorating small surfaces
by means OF an air-brush seems TO
have reached its highet development
in Germany. OF the two types Of APP
paratus, one Is held like pencil and
the other is used like n revolver, ana
the air for spraying Is supplied from a
cylinder of compressed air or car
bonic acid gas, or in more print
| tive WAY by a hand pump. II is
capable OF a great variety OF appllca-
tons. The aid-brush can be used for
ordinary industrial painting by any
unskilled workman. while an artist of
some ability can paint flowers and
other designs upon enamel. glass,
porcelain, bronze, paper and even up
on cloth. carpets and other fabrics
It has proved specially serVicoable In
retouching photographs.
Among the substances for which a
la ia IL "a