The evening times. [volume] (Washington, D.C.) 1895-1902, 1901-06-03
THE EFFECT OF HOT WAVES.
Approach of Summer EvOI<es Consid-
arntinn nf the Suhiect.

fants and very young children, are al
most at hand. While it is impossible to
protect ones self from the effect of these
hot spells, it will be of human interest to
learn from the Weather Bureau what is
known about hot waves.
Alvin T Brown. Observer to the Wealth
er Bureau, publishes a paper in the rec
emily issUed Yearbook of the Depart
ment OF Agriculture, a brief excerpt Of
which is given below covering the main
points of his paper:
of all adverse weather conditions.
those accompanying periods of Iong-con-
tinued high temperature are perhaps the
most detrimental to mans mental, physi-
cal and financial welfare A summer
haiIstorm may destroy considerable prop
eTty over a limited area, a high wind may
cause damage of more serious nature, and
i tornado is still more destructive to life,
but all these are local IN their effect, and
their duration is only for a short period
Even a hurricane sweeping up from the
West Indies, carrying death and deyasta-
ton in it's path, affects but a relatively
small portion Of the United States; a
general hot wave, however, with its
blighting and death-dealing temperature
leaves a trail of ruin SO widespread and
50 great that it cannot be accurately
measured.
The loss to the State of Iowa on ac-
count of not wave which visited that
section IN the latter part Of July and the
early part Of August, 1891, amounted to
over S50.0oo,00G a property loss nearly
twice as great as that caused by the Gal
weston hurricane in 1900; and these are the
figures for only one State. As for the
suffering undergone by the millions Of hu-
mainly day after day in those hot-wave
periods, there is no record. nor is one
possible Statistics may be secured as to
the number of sunstrokes, but no data are
obtainable regarding the sick whose
deaths are FASTENED by the abnormaIIy
heated atmosphere.
OF the great crops Of the country corn
and cotton are most liable to injury
through overheatiHg. The damage that
results from this cause is times ap-
pallinE- In most cases the mere lack OF
rain Is but partially responsible for the
blight, as it Is found that the cooking
firing effect of the intensely heated at
moSpheTe Is the source Of much ire
trievabie damage. When affected by
drought alone most crops viii rapidly re-
VIve, If favorable weather follows. in 2
reasonable time. but once the Hfe-giving
properties are destroyed by excessive neat
no amount Of properly distributed rain
faI or sunshine can repair the injury.
Conservative farmers in the West esti-
mate that during a summer Of average
heat damage resulting on account Of oc-
casioHaI seasons Of high temperature.
covering q period Of from three to six
OF nine days. reduces the yield fully %
per cent below what it would be under
( favorable circumstances.
a hot wave is regarded as a period Of
three OF more consecutive days. during
which the maximum temperature reaches
or passes 81 degrees, With but few
minor exceptions these periods are found
10 occur ia the months OF June. July. Au-
/ gust, and Sept =L Der. In June, as a rule
( the hot waves are less frequent and not
! as severe as later in the season. The heat
! = less. intense. as the cumulative effect
! OF JLe summer season mas not reached its
{ maximum In the farming districts Of the
! y est II Is generally month Of abundant
moisture For most cereals an excess Of
/ heat at this time is the one thing most
( needed, corn and kindred crops being
/ especially benefited. In some not very i'm
/ RoTtant ways hot waves may be OF ben
eut but the amount OF damage done as a
( Whote, more than cOunteTbalances any
/ good which they may possibly do.
Taken as whole, the harvest returns
for years during which hot waves were
unusually severe show q production OF
ODe-fOurJh less in crop quantity the
quality being quite inferior to the stand
. ara however, during the years lTuue-
Olately following such seasons the yield
; frequently reaches q maximum for the
! decade Frequently the hot weather of
/ one summer IS Of material benefit in pre-
PariRS the soil for an unusually large
crop the following season It seems 10
nave the effect Of making the ground
mellow and putting IL in an ideal COndi-
+ ton Tor the reception OF seed
At tunes only one section Of the COun-
( try IS affected. On other occasions large
areas covering half the United States.
! are neld IN the grasp Of the hot wave. 10
! section entirely escapes, although the
5 conditions vary IN different portions. In
! central California eastern OREGON. and
/ eastern Washington the local surround
/ lngs are favorable for IOng-cOntiuutd pc
/ mods OF excessive heat, as ideal sum
! mer conditions exist in these places.
/ mere IS an almost total absence OF rain,
/ ana the summer drought brings with il
! temperatures that frequently pass the IHJ-
! degree mark on several consecutive days
I on the Great Plains of the Middle West
! to most severe effects of the hot wave
aye noticed. II is in this section that the
I hot wave frequently has its birth. X is
I often attended by hot winds. which bear
/ Of the tornado To the general cyclone
/ These hot winds are a constant menace
/ to the crops OF the Western prairies. In
/ many instances fields which promise
/ abundant yeids have been injured be
: yOnd recovery IN q single day. To the
I eastward of the Great Plains the hot
{ wave Is not 50 severe with regard TO its
/ extreme temperature, but it IS usually
! Of longer duration. The effect on VCgCta-
4 ton is less marked although on account
/ OF the higher relative humidity the dis
{ comforts to man are much greater. IN
/ the South the conditions are of d semi
/ tropical nature. the changes being less
I frequent and its diurnal range less. This
/ Is partly due to geographical position and
/ partly TO the fact that the storm tracks
/ pass far 10 the north and their influence
{ is but little felt in this region The South
! does not entirely escape. however, and
/ at times suffers severely from the abnOT-
! NAL heat.
/ In the Ohio Valley, Tennessee, and the
/ Atlantic Coast States the duration of the
/ hot wave reaches q maximum. at times
/ embracing period of two and even three
I y eeks- During these periods. when the
| maximum temperature is above 80 degrees
I daily. the maximum rarely registers low
( ct than 20 degrees, and frequently not
/ that low
/ To this fact may be traced the intense
| suffering Of those who are compelled to
{ live in the large Eastern cities. where
/ the street temperatures are higher than
I those recorded in the Weather Bureau OBJ
! serVatOTieS. On account of the proximity
! rounding the Great Lakes, as well as
! New England. is largely free from severe
/ hot waves The frequent passage Of
! storm centres over these sections keeps
/ the air in circulation and prevents stag
| nation. which seems to be an essential
/ factor In the evolution Of hot wave.
( Along the cOast-iine hot waves are prac-
! ticalIy unknown, due. no doubt. in large
measure to the land and sea brceZeS
! which tend to keep the temperature low
( or than further inland
/ A general idea of Western conditions
( to be expected during hot waves is OBJ
| tainable- The location of the centre Of
! extreme heat viii generally be found on
/ the northern and western outskirts Of the
/ high pressure. The longevity Of the hot