Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1885-12-25
some specimen cola VVaye.

Not merely meteorologists, but every one
who has shivered In the boreal blasts that
come bowling over the country in winter,
will feel interest in the data collected by
Lieut.. Thomas NJ. Woodruff of the signal
service and published in the pamphlet, "Oold
Waves and their Progress" The writer ex.
plains in the hrst place what he calls 'cold
wave" As the ordinary rise and fall Of tenn
perature daily is 1Oo or l5o. and in some
places even more, q fall must exceed these
figures, therefore, to be abnormal, and, in
order to limit the field Of study to the best
specimens, Lieut. Woodruff reviews only
such changes as exceed the ordinary dinrnal
variation by ct least l5o.
In the first six months of 1881, 1882, 1883
and 1884 he finds SS such inttances. OF
these 20 occurred in January, 20 in FebTus-
ry, 20 in March, 10 in April, in May and
10 June All OF these originated in the
northwest, fully S5 per cent. coming into the
United States from the British territory ly-
ing east Of the Rocky Mountains, and the
other 10 per cent. entering from the Pacific
coast of this country or further north. All
but of the SS appeared first at Helena in
Montana, and these were frst discovered at
Bismarck, Dakota from which the cOnclu-
sion is drawn that the cold waves originate
in the Arctic fields OF ice aud snow, far north
| of any of our stations. In their progress
across the United States they took one OF
| three tracke slightly more than half-47 OF
| the SS moving in a generally southeasterly
direction and overspreading the whole coun.
try one equarter-22-moVing from west Ia
east across only the northern section of the
United States, and less than q quarter-l9-
pushing first to the Gulf states and then com
ing up into the Atlantic states. Lieut.. Wood
ruff indicates that the progress and intensity
| 81 a ka fha -
| of a storm in it's immediate front, and hence
the course of the polar flood is similarly con.
trolled. II the storm originate in Texas ol
the Gulf OF Mexico the suction from the
north in its rear, or west of it, will draw the
cold wave down toward the Rio Grande and
| lower Mississippi, and then the fall in tenn
persture will follow the swirl up across The
| country to New England. But if the storm
come from the northwest, and traverses the
great lakes, or go even as far south as the
Ohio valley, the Southern states usually es
cape the chill altogether.
From an analysis of the figures given il
an appended table it appears that these cold
waves are felt with greater severity in the
northwest than in the regions bordering OF
the Atlantic and even Shreveport, in north
ern Louisiana, suffers slightly more than Chi
cago. Bismarck carries of the palm. A
that station cold waves wrought a chang,
of 500 or more in less than a day. In on'
case the fall amounted to 64o in another Il
$50 In II other instances the drop was 40
or more and in 10 more II amounted to o
exceeded 30o. Omaha comes next in order
which shows that the Missouri valley is
favorite pathway of these visitors. Frou
that point six cases were reported in who
the drop was 50o or more, one being $50 AM
another 60o; 10 others we're 4Oo or more, p
others were 800 or more. Helena ranks thir
among the IA stations included in the table
There 50o was reached or passed four times
400 FIVE times and 3Oo eleven times. Tn
greatest fall mentioned at Shreveport anon
the whole 6S cases was one of exactly SO
Nine times It was 400 or more and "a time
il was 800 or more. Chicago reports nine Q
40o or more, two OF them amounting to AZ
aud 18 others reaching or exceeding so
Boston reports only four instances OF ia
amounting TO 400.
The cause OF cold waves, Lieut.. Woodru
says, is not yet understood. He explain
that in various Investigations aud studies
has been shown that fall Of temperatur
succeeds or follows an area of low barom'
tor aud a rise preoedes such an area, an
asks the following question "Is the col
the effect Of an area Of high barometer, o