The Princeton union. [volume] (Princeton, Minn.) 1876-1976, 1879-06-04
~ SPOTS ON THEisUN. 1ahl n
They Will be Numerous the Next Two Years
"A Number Now Visihle. @ &

The period is approaching when the
greatest number Of spots appear on the
solar surface. Even st the present time
several are visible, and some of them of
considerable size. A number Of facts
seem to warrant the opinion of. perhaps
majority Of physicists that the change on
the disco Of the central luminary which
the spots show to be taking place in9
fluence many phenomena on the earth.
The variations, therefore, from uniform
brightness on the great orb Of day are at
present watched with an interest which
was unknown in the infancy of optical
and astronomical science. The discovery
Of the checkered physiogomy Of the solar
orb is due to Galileo,. though accounts of
variations in the SUMS Light date as far
back as the reign Of Augustus Cesar. In
April, 1851, soon after the invention Of
the telescope, spots were observed by the
Florentine astronomer, and nearly at the
same time by, Schreiner, a German
Jesuit, d and dr. abricius, - the
friend Of. Kepler. Being unraquainted
with =, any means of diminishing
the intense glare, the first tele-.
scopists were obliged to make their obs
servations through thin clouds or, when
the sun was near the horizon. The blind
ness which embittared the latter days of
Calico was no doubt caused by watching
the sun spots, and the elder Herschel
lost one Of his eyes in consequence Of his
close stuoy of the solar phenomena
It has been found from the examina-
ton of a long series Of observations that
the time of the greatest number of spots
recur in about eleven years: The last
took place in the, summer of, 1871, In
that year and the preceding they were
frequently observed and measurements
made of their size at the observatory in
this city. On two occasions spot was
observed with the naked eye which, was
j; at least $4,000 miles in diameter In
i 1889 spots of29, O00and even "a 900 miles
are recorded. In 1916 they were seen on
J, several occasions without the aid of the
: telescope. ,,ft RI z;.s.r,,.,. st ,.,:.-,,.-.
! The readiest way to observe the spots
, is to receive the image of the sun either
: on screen or paper marked by perpen-
7 dicular, and horizontal lines at an equal
}, distance from each other. Not only the
8 outlines of the spot, but also its relative
: size. can thus be easily traced. Many
theories have been brought forward to &C
count for the spots on the solar surface
+ especially since the rose-colored flames
q which appear during total eclipse Q
t. that luminary, have been shown to b
# caused by hydrogen gas. But with tn
e exception Of this fact and the NANTES
> effects of cyclone-like waves which RS
i, and produce disturbances in portions c
It its districts, the true causes of the chang
D. es on the suns surface with the exception
Of of those produced by some Of the planet
le as well as the sources Of its heat an
nj light, are unknown. Observations of th
le spots now appearing, and which will bt
y come more numerous during the ne1
two years, may enable physicists to d.
III termine many questions connected wit
ut the central luminary which are now VI
r answered. The older Herschel suppose
re that the average temperature Of years
u which large number Of spots appear G
Of the solar surface IS generally lower. TIL
n, has not yet been fully proved, yet Il
~ summer Of 1916, so remarkably for lar!
be spots, was the coolest on record in t
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