The New York herald., 1921-11-20
The Dust Blanket of Outer Space
IL Is Formed of Volcanic Dust and Is One Cause of
Exceptionally Cold Winters.
By JACQUES w. REDwAY.


So far as New York city and its vicin-
ity are concerned a winter In which the
average of any two consecutive months
is below 27 degrees may be regarded
as cold; this occurs about once in hve
or six years. In the last hundred years,
since temperature records have been
kept. there have been several very cold
winters OF these the winter of 1918
EQUALS that of 1S67-6S in its low aver
age and surpasses 1t In the lowest tenn
perature recorded in century.
There are no records preceding those
begun at Fort Columbus In 1922, but
the literature of the fifty years preced-
ing contains some interesting facts
which explain a possible cause OF cold
winters These records cover the Attain
tic States from Maine to Chesapeake
Bay. Here are the records and the au-
thority for each.
1771-From the Netosletter, Boston :
"At Stratford the Sound is frozen three
leagues across and people ride every
day to Long Island"
17s0-From Thomas Jefferson's diary
chesapeake Bay is frozen solid to the
mouth of the Potomac" In the same
year Noah Webster writes: "rhe Sound
Is covered with ice between New York
and Staten Island and troops crossed
from New Jersey to attack the British"
17S3--From the Philadelphia Inquirer !:
Delaware River was closed as carly as
November 2s, and continued icebound
until March 49," The winter Of 17S3-S4
was one of the severest in history, as
will be noted in another paragraph.
1S16-From a letter written by Pro-
fessor Dewey, Williamstown, Mass. :
"There was cold weather every month
this summer: on June z. light snow"
From Thomson's History Of Vermont" :
"On June snow fell in all parts of
the State; on tho uplands 1t was five or
six inches deep. 1t was accompanied
by hard frost, and on the 9th Ice was
half an inch thick on shallow standing
water Corn and other vegetables were
killed"
A reason for the cold year OF 17s3-S4
and also for the summerless year of
1916 is not hard to find. The dry fog
mentioned by Franklin was a thick
cloud Of volcanic dust or ash elected
from Hekla and Laki, two volcanoes in
Iceland. Asama. q volcano In Japan.
was in eruption about the same time.
During the three or four years preced-
ing 1915. the year Of "eighteen-hundred-
and several volcanoes
were in eruption. One Of them. Tam
bora, cinder cone Of the Dutch West
Indies. darkened the air with dense
clouds of dust for many days.
The dust Of volcanic eruptions differs
from ordinary clouds in many respects.
Clouds are produced by condensation OF
water vapor in the air; they are COM
paratively thin, rarely more than a few
thousand feet in thickness. Moreover
they are not extensive in area: still
more, they seldom prevail for more than
two or three days at time. Therefore
they do not screen the heat Of the sun
for any great length Of time. The blan-
ket Of volcanic dust, on the other hand
is anywhere from twenty to twenty-five
miles in thickness, and 1t may remain
in the air for two or three years, OF
even for longer time, as was the case
In 1S12-16.
A screen of volcanic dust may not be
visible except as it occasionally tinges
the sunset sky. 1t is dense in the local
ity Of the eruption only. But from the
time II Is shot into the air until II
finally is brought to earth it Is a screen
which constantly intercepts more or less
OF the suns heat. Moreover, It is no:
confined to a small area; 1t may cover
and envelop almost the whole earth.
From the time OF Franklin UP to 1884
practically no thought was paid to dust
blankets Of volcanic origin so far as
climatology Is concerned. The eruption
of Krakatoa, a volcano in the Strait OF
Sunda, and the famous red sunsets re.
sulting therefrom attracted universal
attention to the optical effects of at
mospheric dust; the unusually cold win
ter Of 1SS4-S5 brought to mind Frank
Inns opinion concerning such dust as a
factor In forecasting cold winters
Franklin said "From such fogs men
might conjecture the probability Of a
succeeding hard winter and of the DAM
age to be expected by the breaking OF
river ice in the spring."
The opinion was certainly worth con-
sideration then; 1t Is worth considera-
ton at the present time. With the aid
Of airplanes--and they have reached the
altitude of more than six miles--sur-
veys Of the dust content Of the air may
be made with fair degree Of accuracy
and 1t is not improbable that in the