Phenix gazette. [volume] (Alexandria [D.C.]) 1825-1833, 1831-08-25
THE SOLAR PHENOMENON.

- The SoLAlt PtiENU'IENo-''
We are obliged to respectable friend IN Al
exandria for the following interesting observa-
tons upon the late extraordinary appearances
connected with the sun.-Na. Int.
ALEXANDRIA BoAHptSG School.
9th Month. Goth, 1881.
Friends Gales & Seaton: In compliance with
the suggestion in your paper received to-day,
send you the following views respecting the very
unusual, If not unexampled appearance II the
sun, observed few DAYS since.
10 understand the phenomena a!iuded to, it
will be necessary to make few preliminary OBJ
servstiops. During the great total eclipse of The
sun that had recently taken place, the moon had
inst pas ed ITS perigee Or that pont Z! lis orbit
nearest the earth. and consequently the conb'n-
ell action of tie sun and m0on |Fon the atmos-
phere produced great tide 10 tn :GnaToria: re-
sinns, and diminished the pressure OF 'he ar up
on the whole uf the surface OF the earth. his
diminutiun of pressure upon the surface OF the
water would occasion ggeal Increase "i cFapo-
ration, particularly when united with the ihsh
Temperature that accompanied it. For 1t Is al eS-
tablished fact. that the amount OF evaporation
from an uunnsulaied sar!ace ii water depends HD-
on the elevation Of temperature and ,ilmnnahn
uf pressafe. a vast quantity oil Hap"r tiius rti'-
ed was verv ob aervabe the evening OF the t2ih
| inst. at considerable elevation, in tie western
| part of the heavens. and continued To reflect a
very red isht FOR a long time after the sun had
| set.
| The appearance Of the heavens on the mn.n-
ing of the I3th did not observe; but about mid
day, the sun shining through this body Of vapor
had siiyery appearance ssuslar 10 that which 1t
wears when shining throug vanishing fog. & OBJ
served it to give UNUSUAL, CHASTITY to
the countenances of persons. Between three
and four o'clock, the position Of the sun, with re-
spect to this body Of vapor becoming changed. 1t
assumed greenish blue appearance. precisely
similar to that produced by the following expert
ments. and which in my opinion was dependant
upon the same cause. Let screen upon which
the spectrum produced by the separation Of the
solar beam INTO its primitive colors by glass
prism is thrown, be pei forated 50 as to let all
except the red ray fall upon double convex
lens, and lie conveyed To focus, the result will
be representation Of the sun Of srcenish blue
coEar, exactly such as it was observed to have at
the time alluded to. The color is that resulting
from the combination Of all The primitive colors
except the red, aud is denOminated in optics the
Opposite color.
The same experiment may be performed more
Familiarity thus: Place red wafer upon a white
wall, and look at il intenuy with one eye for some
time; then let the eye rest, without much effort
at seeing, upon the wall. ard SPOT, the size of
the wafer. Of sreenish blue color, will be per-
oeived The explanation is. that The retina,
through the action upon i, by the red light from
the wafer, becomes insensitle TO the red raw in
that part upon which the image Of the wafer rest
ed, and hence the color produced upon that part
n 81, NIL h, ali 4, In.
combination of the other six.
The greenish blue color Of the sun. then. |
think. depended upon the red rays being reflect
ed by the intervening body OF yapor, while the
other six passed to the eve, and produced the OBJ
served appearance This opinion was strength
ened By one or two facts observed at the time. |
passed the suns ray through a prism. and while
the yellow, green, blue, indigo and violet colors
appeared with their ptoporonate brightness, the
orange was considerably less distinct, aud the red
much less than the orange.
! Another corroborati,e fact was, that as the sun
decended below the body OF vapour, which was
about fifteen or twenty minutes before its setting
, the vapor reflected an intensely red lieht-the
light that passed thro it was therefore separate
from the red, and would have produced the OPP
posite. or greenish blue appearance.
The spot that was observed. IS by no means an
unusual thing upon the suns disc. 1t was visi-
bic to the unprotected eye, merely in consequence
of the diminished brightness Of the sun. BY aid
of a telescope, a considerable number of spots
were visible. In the summer of 1916. spot
was visible 10 the naked eye for eight or ten days
in succession.
If the above remarks are any way satisfactory
TO you, it will be qualification to
Your sincere friend.
BENJAMIN HALLOWELL.
> It's evident, that as the air is partially sup.