The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1878-07-29
Interesting Experiments with Edi-
sons Instruments.
REMARKABLE RESULTS.
Solar Mysteries Which the Swans De.
sire to Solve.
ANXIOUS FOR GOOD WEATHER.


completed. To-day the last nail driven In the
temporary structure OF pine boards which
an observatory The latter is situated about eight
hundred yards from tho depot, at short distance
from the base OF range oil hills and commands
excellent view. the observing party consists Of Pro-
lessor Henry Draper, Of the University Of Pennsyl-
vanin; Professor Thomas A. Edison, OF Menlo Park;
Professor George F. Barker Of tho University Of Penn
syIvanis, and President Henry Morton. OF the
Stevens Institute Of Technology. Accompanying
the party Is Mrs. Henry Draper vile OF Pro-
lessor Draper, who also takes part In the
work of observation, being quite an euthu-
siast In the study OF astronomy. Tho instruments
brought here by the astronomers comprise several
telescopes and spectroscopes Photographic apparatus
Edison 3 tasimeter and numerous other appliances OF
the latest and approved patiern. All now 10
readiness and several prslim mary experiments have
demonstrated that transportation has not Injured
them. Tho man point sought to be determined by
Professor Draper Is whether tho corona halo
rounding the suns disk is only q glowing gas, or
whether It contains. in addition, solid liquid par
tlces that reflect light from the TO the oarth II
the corona is simply glowing gas the spectrum will
consist Of bright lines Oriaht rines only, but II
there arc any solid or liquid substances reflect
ing light In the corona The spectrum will be Of q
faint continuous character. containing all the colors
WHAT IS TO INVESTIGATED
The sup, according to best accepted theories Is
q solid or liquid raised 10 high a temperature
that It gives white light. linn edia,ely surround
ing Is envelope called tho ch romospherc, which
to the naked eye appears OF rosy tint Outside Of
this is another envelope, nearly white called the
corona and outside OF all Is FAINTER white mate.
rial corona extending, It IL estimated dis-
tance Of $780, 600 miles. In the older eclipses-i e.,
those which prior TO twenty years ego. this
corona which Is tho main object scientific tr-
vestigation, received but little attention 1t was
not digniaed by a name Astronomers
spoke OF It as tho "slaro' "halo"
or .'rosiusss." Nobody thought 1t worthy OF study
In 1860, whom photography for the first time was
called in as an aid interest became centred In it.
1t not however, until 1868 that It's importance
a base OF astronomical research became fully appar-
cut In that year the spcctroscope nrst applied,
It revealed The that this halo which In tho
meantime had been scientifically named corona"
composed OF hydrogen gas, together with, In .
MINOR degree, some unknown substance, which TO
this day continues q mystery. This unknown ma
ter,al "a designated by tho term "helium"
TIE srxcrRoscorE
BY Ihs Invitation OF Professor Draper your CORE.
spondent to-day visited the observatory and viewed
some Of tho experimental solar spectra taken by
means OF the spec,roscope. This little instrument,
which has proved valuable In iathoming the mys.
romem.
bsrsd, Of = small brass cylinder somewhat rcssm.
bling diminutivs telescope. A. end 10 . thin
metal disk, IN tho centre OF which 10 cut a narrow
slit to admit ray Of light Arranged inside OF the
cylinder lenses and prisms. Whom q ray Of light
from the sun penetrates through tho slit Il becomes
at once dccomposed into Its constituent colors,
making vislbe q beautiful band like q miniature
rainbow, RED ut one end and blue at the other.
This band is known as the spectrum. Across
the surface Of the spectrum discernble
at irregular Intervals numerous Gpo black lines.
II instead of sunlight light from tho flame OF vapor
iron metal ignitod to n white heat 10 allowed pass
through the slit another band appears less beautic
by Of the absence of OF the colors, but
containing similar nne Ines with, however the Im-
portsut difference that such limos whito OF
black. BY the comparison OF tho lines produced by
tho hight OF any metal with those produced by the
light OF the sun the presence In the latter OF suoh
metal Is determined Exact similarity proves that
the same subsi auce produced both In this way the
presence In the sun OF many metals and gases CON-
the earth hes been ascsrtained
PHoToGRApmyG THE coRou
One Of the chief oiGisutiss In previous OBJ
servatons has been TO obtain an image OF the
corona sufficiently bright to photograph. This diff
Guilty. however. promises on the present occasion to
be overcome. To his large equatorial telescope Pro.
lessor Draper has attached instrument designed
by him, which copdcnses tho image OF the sun into
lees than oneiourth Of an inch In diameter ana con
certrates she to such degree that white paper
held Immediately underneath Instantly set on nre.
Just oofore the suns rays come TO focus . ruiod
plate technically called . ''dinrsciion grating" Is
placed the OF rays a angle oil about sixiy
dsgrcss This ronects the light one side, and as
tho same tme dwperscs It into q series Of speosra
At tho focus OF the instrument are placed three
ceivc q plain image Of the sun. the other two viii
receive each spectrum Of the corona, but ono will
bc twice as much dispersed the other. BY this
arraneemsnt Professor hopes 10 double tn srdi
nary chances OF success the observation. the OBJ.
ject taking the central plain image tho sun is 70
have standard OF comparison for tho two spectra 80
as TO 500 how they compare In height with H.
spisoy's WORK
Professor Edison Is part of work on the day of
tho eclipse will be TO observe with his tasimeter at
tacned 10 large telescope whothsr tho corona gives
out any heat Hitherto no researches have boon
made In this direction. Al tho moment to,aty or
whom the entire disk OF tho sun 10 obscured
by the moon, no will direct his instruments
a. the moon in order TO get the "zeron
point tor his gaIvaBometsr. This accom- plishcd
no will change It's position 10 bear on tho corona
n the aor emits suelcn the needle OF his gal
vsnomster will indicate the same During the trial
the galvanomes aud tas meter viii be carefully en-
closed In suitable apparatus nov being made
tor the purpose. The only dnlcuty which Professor
Edison Tears Is tina, they may prove 30 exceedingly
sensitive that exraneous influences Surrounding may
divert them IRON their proper work. Every preoau.
ton. however, will DO taken TO avoid such result
DIVISION LABOR
The work assigned to Professor Barker 10 OBSERVE.
ton with powerful telescope and spectroscope He
will particularly direct his attention to the Identified.
ton OF certain lines Of the spectrum, about which
at present but very little is known. Pres-
dent Morton's observations Will be directed to-
ward examining the corona with view TO ascertain
whether or not lis poisrized For this purpose he
will employ . polarization instrument, which will
show wnsthsr any Of thu light OF the corona 10 re-
wh~