The times dispatch. [volume] (Richmond, Va.) 1903-1914, 1913-04-27

volcanic dust is the curious

discovery made By Professor
G.. G. Abbot. Director OF the As,ro
physical Laboratory of the Smith
sonian Institution, of Washington.
His conclusions are published In
pamphlet called volcanoes and
Climate just issued by this insti-
tuition.
From this 1t appears that the re
markedly cool Summer which we
experienced last year must be at
trlbuted 10 volcanic dust
The professor made this discovery
while observing the sun at Rassour,
Algeria, for the purpose OF compar-
Ing temperatures with those taken
st Mount Wilson. California. He
was working on the hypothesis that
the amount OF heat given off from
the suns surfsce varies in different
years. While this hypothesis has
not been disproved, IL has been con
~iderably modified by his recent OBJ
Eeryations.
lie was puzzled TO observe very
persistent reddish haze in the sky
above Bassour. Observation showed
chat II could not ne -vapOr cloud
Reports from Mount Wilson in
formed him that Il similar haze WAS
visible there. Investigation proved
that this could only be due 10 the
tremendous eruption OF Mount Kat
mai. near Alaska, which occurred on
June 6, 1912.
a long series OF intricate calcutta
tions indicated that the volcanic
dust in the atmosphere reduced the
amount of heat received from the
sun by about 10 per cent. II would
produce 4 fall OF several degrees
Fahrenheit perhaps five or six
from the mean average temperature
of the year
From our Bassour (Algeria) ex-
perimepts," writes Professor Abbot,
in his report, Including the meas
urements ny two methods of the
radiation Of the sky, it appears that
the quantity of heat available 10
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 decrease In the
earth's radiation 10 space, caused By
the haze
One method OF measuring the heat
was by the spectre bolometcr, in
vented by the late Professor Lang.
ley. This instrument shows By
spectroscopy the amount OF heat
distracted from a pure ray of sun
light by the atmosphere and all the
substances in il.
Professor Abbot calculated that
the amount OF heat ordinarily lost in
Summer by radiation 10 space was
005 calories per square centimetre
per minute. while during the prcva-
lence of the volcanic dust it was 02S
calories. showing 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
go through an eleven-year cycle OF
increase and decrease 1t has been
noticed that there is Il fall from the
average temperature at the point OF
maximum sun spots. The year 1912,
however. was not year OF max
imum sun spots, and this strength
ems the evidence that the fall of tenn
peraturc was due TO volcanic dust.
The fall was much greater than has
usually been found TO occur in years
of maximum sun spots.
The loss of heat is of course, Que
to the interpretation 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 if il prevails
shortly before the beginning OF Win
ter or just after that season In that
case ii would cause an abnormal ac-
emulation 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 it seems quite possible that if
they should come at the end of
long and severe Winter they might
create practically a!l-the-year
Winter.
aThat would he calamity of
worldwide magnitude. 1t would
meas tho failure OF the craps over
the whole of the United States and