The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1869-09-16
POPULAR SCIENCE.

n
Hkithough l find 1t generally best for sketch
ing purposes to have the open slit in radial
diTection, have lately placed 1t at tangent to
The limb in order to study the general outline
of the chromosphere, which in a previous COM
munication stated to be pretty uniform, while
M. Jansen has characterized 1t as "a ntredu
fort ineedl ct tOurBente.' My opinion is now
that pefhaps the mean of these two descriptions
is asusuai, nearer the truth unless the surface
changes its character to q large extent from
time to time. j find, too, that in different parts
the outline varies; here it is undulating and bill
lowy there it is ragged to degree, hames as it
were, darting out of the general surface, and
forming a ragged, fleecy, interviewer outline,
which in places is nearly even for some dis
tance, and, like the billowy surface becomes
excessively uneven in the neighborhood of a
prominence. According to my present limited
experience of these eXquisitely beautiful solar
appendages 1t is generally possible to see the
whole of their structure; but sometimes they are
ofsuch dimensions along the line of sight that they
appear to be much denser than usual and as
there is no longer under these circumstances any
background to the central portion, only the de-
tails of the margins can be observed, in addition
to the varying brightnesses. Moreover. it does
not at all follow that the largest prominences
are those in which the intensest action, or the
most rapid change, is going on-the action as
visible to us being generally confined to the
regions Just in or above the chromosphere, the
changes arising from violent uprush or rapid
dissipation, the uprush and dissipation repre-
n rule the attachment to the chromosphere is
narrow and is not often single; higher up the
stems so speak, intertwine, and the prominence
expands and scars upwards until 1t is lost in
delicate filaments, which are carried away III
floating masses.
"Since last October, up to the time of trying
the method OF using the open Slit had OBJ
tanned evidence of considerable changes in the
prominences from day to day. With the open
slit it is at once evident that changes on the
small scale are continually going on; it was only
on the 14th inst. that | observed any change at
all comparable in magnitude and rapidity to
those already observed by NJ. Jansen. About y
hours 45 minutes on that day, with t0ngential
slit | observed fine dense prominence near the
suns equator, ON the eastern limb. | tried to
sketch it with the slit in this directions; but its
border was so full of detail, and the atmospheric
conditions were so unfavOrable, that | gave up
the attempt in despair. turned the instrument
round 80 degrees, and narrowed the slit, and my
attention was at once taken by the line a
single look at it taught me that an injection
into the cromosphere and intense action were
taking place At 10 hours 80 minutes when
the action was slackening, l opened the
slit; | saw at once that the dense appear
ance had all disappeared, and clOud-liie fila
ments had taken its place. The first sketch,
embracing an irregular prominence with a long
perfectly straight one which | call \, was fin
ished at II hrs. min, the height of the promi-
nence being min. sec, or about 1900 miles.
left the observatory for few minutes, and on
returning at II hrs. ID min, was astonished to
find that part of the prominence A had entirely
Disappeared; not even the slightest rack ap-
peared in its place; whether il was entirely dissi-
pated, or whether parts of it had been waited
towards the other parts, do not know. although
i think the latter explanation the more proba-
BILE one, as the other part had increased"
Mr.. Lockyer threw fine picture of this storm
in the sun upon the screen.
Radiation of Heat from the Moon.
The Earl Of Rosse is making a series of eX-
periments by means of a thermo-pile of four
elements and a three-foot telescope, to deter
mine, if possible, what proportion of the moons
heat consists Oft That coming from the
interior of the moon, which will not vary with
the phase; 2. That which falls from the sun on
the moons surface, and is at once reflected
regularly and irregularly: 3. That which falling
from the sun on the moons surface is absorbed,
raises the temperature of the moons surface,
and is afterwards radated as heat of low refran-
gibility. The chief result arrived at up to the
present moment is that Che radating power of
the moon being taken as equal to lampblack
and the earth's atmosphere supposed not to
affect the result a deviation of 80 degrees for
full moon appears to indicate an elevation of
temperature equal to 500 degrees Fahrenheit
The relative amount of solar and lunar radiation
was found equal to S9Sl9 l.
Action of Sunlight on Mineral Oils.
some curious experiments, recently made by
Herr Grotowsky, on the action of sunlight upon
mineral oils, show that when the different kinds
OF petroleum oils are exposed to the influence of
sunlight, they absorb oxygen from the air and
convert it into ozone, as has been shown already
for many other hydrocarbon oils by Shoenben
Kuhlmann, and PhipsOn. According to Pro-
lessor Grotowsky no chemical combination oc-
ours between the oil and the ozone; the latter
remains free, and oXidizes powerfully any sub
stances brought into contact with it. The odor
OF the oils is completely modified when
they contain ozone;-the author states
that they cannot be burnt, and
that they rapidly attack cork The color of the
glass bottles in which the oils experimental on
are enclosed has marked influence on this alb
sorption of oxygen. Preserved in iron vessels.
or completely out of the rays of daylight, all
these oils may be preserved intact; but in white
glass jars exposed to the light, the white oils
become yellow, are highly charged with ozone.
increase in specific gravity 0O05, burn with
much difficulty, and attack the corks of the
bottles. This is particularly the case with Ame-
rican petroleum.
Che OxyhydrOgen Light.
Ihls scheme has now taken definite shane in
Parls. company has been formed the capital
necessary has been raised, and application has
been made for permission to lay down pipes to
carry oxygen and hydrogen over about fourth
OF the city. 1t is not very likely that the per-
mission Will be granted, and the promoters will
nave TO coniine themselves to supplying indivi-
duals with compressed gases as was originally
proposed by the patented processes NJ. Tessie
d9 Motay obtains the oxygen and hydrogen
which he proposes to distribute over Paris, at q
Cost solow that the oXyhydrogen light is promised
much cheaper than common gas light but
ingenious and relatively cheap as they undoubt'
eQy are, II is impossible to believe that the SER
vice can be made SO inexpensive as to supersede
coal gas. The prospectus of the company en-
iarges upon the cheapness and purity of the
light the complete combustion, andth absence
of all deleterious matters in the products OF the
combination; but is quite silent as to the danger
oi Introducing into house two gases not pos
sessing any SMELL and which, consequently