The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1913-05-04

discovery made by Professor
C.. G. Abbot. Director of the Astro-
physical Laboratory of the Smith
eonian Institution, of Washington.
His conclusions are published In
pamphlet called volcanoes and
Climate" just issued by this insti-
tuition.
From this it appears that the re-
markably cool Summer which we
experienced last year must be at
tributed to volcanic dust.
The professor made this discovery
while observing the sun at Bassour,
Algeria, for the purpose Of compar-
ing temperatures with those taken
at Mount Wilson, California. He
was working on the hypothesis that
the amount of heat given of from
the suns surfcce varies In different
years. While this hypothesis has
not been disproved, 1t has been con-
etderably modified by his recent OBJ
servations.
He was puzzled to observe a very
persistent reddish haze In the sky
above Bassour. Observation showed
that 1t could not be vapor cloud.
Reports from Mount Wilson In
formed him that similar haze Was
visible there. Investigation proved
that this could only be due to the
tremendous eruption OF Mount Kat
mai, near Alaska. which occurred on
June 6, 1912.
a long series of intricate calcula-
tions indicated that the volcanic
dust in the atmosphere reduced the
amount Of heat received from the
sun by about 10 per cent. 1t would
produce q fall of several degrees
Fahrenheit-perhaps FIVE or six
from the mean average temperature
OF the year.
From our Bassour (Algeria) eI-
periments." writes Professor Abbot.
In his report, including the meas-
urements by two methods OF the
radiation Of the sky. it appears that
the quantity Of heat available to
warm the earth was diminished by
nearly. or quite, 10 per cent by the
haze. There Is, however, some in
dication that this was In part coun-
terbalanced by a decrease In the
earth's radiation to space. caused by
the haze"
One method Of measuring the heat
was by the spectro-bolometer, in
vented by the late Professor Lang
ley. This instrument shows by
spectroscopy the amount OF heat
abstracted from a pure ray OF sun
light by the atmosphere and all the
substances in 1t.
Professor Abbot calculated that
the amount Of heat ordinarily lost in
Summer by radiation to space was
o.05 calories per square centimetre
per minute. while during the preva-
lence of the volcanic dust 1t was 0,2S
calories, showing a loss of 0.20
calories TO the earth through this
cause.
Volcanic dust now appears To be
the chief factor In causing cold
years. Hitherto the variation In
sun spots has been regarded as the
determining factor. The sun spots
60 through an eleven-year cycle OF
increase and decrease. II has been
noticed that there Is fall from the
average temperature at the point Of
maximum sun spots The year 1912.
however, was not a year OF max
imum sun spots, and this strength
ems the evidence that the fall of tenn
PcTdlbIC was uuS 10 NOlCdHlC uust.
The fall was much greater than has
usually been found 10 occur IN years
OF maximum sun spots.
The loss Of heat Is, OF course. cue
TO the interposition OF a layer OF
minute floating solid PARTICLES which
prevent certain proportion OF the
suns rays from reaching the earth.
The effect OF the volcanic dust Is
very much intensified II IL prevails
shortly before the beginning OF Win
ter or just after that season In that
case Il would cause an abnormal &C.
cumulation Of ice and snow and. an
unnatural prolongation Of Winter.
Fortunately, this coincidence did
not occur In 1912. Volcanic dust
clouds may prevail for many months
and IL seems quite possible that II
they should come at the end OF a
long aad severe Winter they might
create practically all-the-year
Winter
That would be a calamity Of
worldwide magnitude II would
mean the failure OF the crops over
the whole OF the United States and