New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1904-07-02
HAS THE SUN BEEN sHIRKING,

HAS THE SUN BEEN SHIRKING?
A paper which Professor s T. langley con-
tributes to the latest number Of The Astro-
physical Journal has an important bearing on
the eccentricitles of the weather for a year
or more. He now makes additions to tables
printed several months ago, showing apparent
fluctuations in the transparency Of the atmos-
phere since the autumn of 1901. and also what
look like changes in solar radiation during the
corresponding period. These figures are coupled
with meteorological data obtained from many
places in the Northern Hemisphere; and the
comparison IS interesting, if not significant
According TO the Smithsonian record the ease
with which the suns light and heat penetrated
the carth's aerial envelope diminished percepti-
bly, at some time between November 49, 1902.
and February 49, 1898. 1t then maintained
lower level than that OF the preceding year,
rose nearly to the earlier standard by January.
1904, and then decreased again. The record
ends with February IL. Inasmuch as the air
is credited with absorbing from one-third to
two-fifths of the solar radiation, d heightened
observation, though not enough TO be apparent
to the ordinary observer might we'll affect the
welfare Of plants and animals, and especially
that Of civilized man. The degree to which
this supposed obstruction operated was not
uniform for all parts Of the spectrum 1t was
believed to be particularly helpful to vegeta-
ton, and from 23 to go per cent in the invisi-
bic region beyond the red rays.
The second set of figures presented by Pro
fessor Langley indicate that outside OF the at
mosphere there was a falling off I'm the suns
output On March 2G, 1908. reduction of fully
per cent was detected as compared with the
average for six or eight earlier observations
that year and IN October, 1902; and by the
close Of April. 1903 the deficiency was fully 10
per cent. The amount Of radiation underwent
trihing variations, but remained about the same
for ten months. \ perceptbe increase was re-
corded late last January. and on February IL,
1904. the radiation was apparently as large as
ever.
So far as dates go. the solar changes corre-
spond more closely with the recent cold weather
than do the fluctuations in the transparency
of the air. In the eastern part of the United
States, 10 be sure, the most conspicuous de-
parture from normal conditions did not begin
until November, and it was greatest in Feb
ruary last. However, when the average tenn
perature for twenty stations in North America
is examined IT will be found that there was q
notable fall early as April The same thing
is true when the number OF stations is en-
larged to eighty-nine and made to include
Northern Europe and Asia. Inasmuch as the
ley's article is limited to the year 1903, it IS
impossible to say whether there was any
serious disagreement between the two records
after the opening Of the current year. No
doubt there are local discrepancies, like that
between the extraordinary weather OF last Feb
ruary in the Atlantic States and the supposed
restoration of solar activity, but these would
hardly signify If the general parallel for the
world close. Moreover, it Is credible that
the obscurity Of the atmosphere, which was OBJ
served IN this country at least six weeks be-
fore the apparent decrease in radiation, and
even earlier in Europe, has not been without
influence; but 1t looks as if changes in the sun
had been the more powerful of the two causes.
Before accepting that opinion, even provision
ally, it is necessary TO consider how much COZ
fidence can be placed in the figures given for
solar radiation. These are obtained, after max
ing one set of observations with a delicate
instrument of Professor Langley's invention
by making an allowance for observation
which is estimated in another way. The Sec
rotary OF the Smithsonian Institution has de-
voted so many years to this kind of re-
search and has eliminated so many possible
causes of error and interference with the OBJ
servations themselves, that other astronomers
are disposed to think that his results are trust
worthy. Independent work should be done in
the United States and abroad, for purposes of
Confederation, if this sort of study Of the sun
proves TO have a practical value. STILL in the
work already done at Washington the attempt
has been made to secure two observations on
the same day, a check the other. In
the thirteen months beginning with February,
1908 twenty-five entries are made for solar
radiation in the table given in The AStrophySi-
cal Journal" and in all but two cases they
are thus paired. Even after the accuracy Of
the work is established, it needs 10 be continued
for years before its utility can be fully deter
mined. A host of questions need to be an
swered before the meaning and bearing of
changes in the suns activity can be known, but
it is not unlikely that the study will prove eX-
ceedngy serviceable.