New-York tribune., 1874-01-01
Sun SPOTS.
oSs OF UNUSUAL MAGNITUDE AND BEILLIANCY DIS
COVERED BY PROF LANGLEY.
The following interesting letter appears in

oSa OF UNUSUAL MAGNITUDE AND BIILLiANCY DIS
COVERED BY PROF. LANGLEY.
The following interesting letter appears in
The Pittsburgh GdseHe of Dec. q:
During the past week spot has appeared on the sun
Of such unusual magnitude as to have been visible to the
naked eye and the occurrence enough 10 attract
attention only from professional observers hut from
all who take an occasional interest IN sUch matters
such large spots, il Is well KNOWN usually are vts
ble II ALL certain definite periods the last te OF
their maxIuuIn having passed some three years ago
and though smaller ones at nearly all times seen
Telescope, it more than two years since any
has presen OF the size of This which, coming so
far OF season, offers spectacle which is not keJ 10
be repeated for several years.
Perhaps, then, | may feel warranted In Inviting az
tentOn 10 spot question: whicn can now he seen
nearing the side OF the sun where II - con-
spicuo GUS with very little optical aid and visible
with attention through smoked glass, looking Ike
small cloud the brightness of the western limb be-
hind which it Will soon disappear. Through great
telescope the spectacle is remarkable over Az smaller
i what over 81 900 miles Throughout TINS extent the
surface broken and tossed into every form lho
which the solar cyclones dstOrt the intensely brilliant
matter on whlch tuey are hctlng' tutVlheIr oull!ts
Che traces left by these whiriwlnd9 predomnate hut
the nricacy ana beauty ol the shapes are beyond com
palisOn with any OF the ulOflns OF our own at
nosplere, they also more defnite In outline
Some are crystal hke IN lhe precision OF ther details
but while the crystalline patterns the frost traces on
windowpanes are not more beautiful or definite.
they cannot rival the VIVID splendor of these solar
FORMS or Drlng mp inc impression we gam when We o-
that vast as the real dimensions must be,
they shifting and passing into shapes from nour
to hour and even visiOly changing while gaze.
The interior Of pudding furnace ia which the white
miniature not wholly unsatisfactory type Of OF
these, and perhaps 10 Pittsburgh reader such
parlsOn will be descriptive any which be
fered The Resemblance nOldS Ia points than one
for iron heated 10 the point where passes into glowing
VapOr OF the prominent ingredients the clouds
and around the spot. = is known that in
blast furnaces a comparatively small quantity Of the
metal vapOrzed out of every charge and the results
ali interesting estimate the total Quantty
OF iron thus dsslpaed IL the smoke OF Pittsburgh fur
naces reaches annual amount OF 5000 tOIs-an
estimate which Is startling but within the truth. With
the help OF tins result ana that OF measurements made
al tue Observatory, which shows that the "spot"
over lGO0OO00O0 square miles, may try
the magnitude Of the action which ills with the
vapOr or iron and the metals every
part OF when is necessarily at temperature
that the blast furnace rival
When thus translate mlcrometric measurements
from degrees aud minutes into the familiar ones
ana yards are met by numbers great
does not possible to realize the quantities they
stand for and thus they grow 50 familiar
as not bring TO the compuOr KIND Of new sur
prise with each verlucatoD. Reckoning In this way,
find that the mnutest apparent dot in all the
plexty OF forms have alluded to- must, for instance,
be Larger in reality than tue Sate OF Pennsylvania to
of least visible magnitude IN powerful tel
escOIes. Though AL have even briefly described
IN ordinary Instruments the smallest Will
vet show enough 10 make the spot" OBJECT Of inter
wnicn Of readers viii, In this holiday
sonp perhaps 1nd some inclination and leisure enjoy
n. u.