The Birmingham age-herald. [volume] (Birmingham, Ala.) 1902-1950, 1906-11-26


Direct Observations.
Evidently the more reliable of this
class of weather forecasts are based on
direct observations of the elements Of
Meteorology as wind clouds and mols-
ture and weight of the air. Winds and
clouds were naturally most observed by
| the mariner for not only did he depend
to some extent on the weather for live
| lhoo!. but also the safety of his ship
and the lives Of his crew and passengers
depended on his constant watching and
accurate interpreting Of weather changes.
| The character of atmospheric conditions
| caused by changes In the wind depends
mainly on the position of the observer
with regard to land and ocean, latitude
and hemisphere. How the winds affect the
weather in this section we will see later
whenwe come to the methods OF forecast
| ing weather employed by the weather
| bureau, but we may mention here an III
! stance of the inconsistency that arises
from attributing all weather changes 10
| a change In a single weather element.
| We expect cooler weather in this section
with all northerly winds. 1. c., winds that
| blow from the northeast, north and north
west but while we may expect fair
| weather with all these winds. that from
| the northwest is almost exclusively dry
and accompanied by clear conditions, and
| the most disagreeable weather comes us-
ually with the northeaster, especially In
winter.
! Winds and clouds are the only weather
elements that can be observed directly.
| Changes in the air pressure and In the
| moisture contained I'm the air are more
| difficult to detect, still, If considerable.
| they act on certain organic and inorganic
| forms in manner that they could not
well remain undecided by the close OBJ
server, and so find a great number OF
/ We "a ha
Under normal conditions the weight or
| pressure of the atmosphere is about a ton
| on the square foot of the earth's sur
| face, and since n grown man exposes
about fifteen square feet of surace to the
| air, the air pressure on the average iui-
| man body Is about fifteen tons. or
| course this causes him no Inconvenience
since tho pressure from inside the body
| Is the same, and eounteracts that from
the outside: on the contrary, the greater
| the density of the atmosphere within
| reasonable limits the higher the spirit of
man, and an American proverb says, do
| your business when the wind In from
the northwest for then the air pressure
is high. and some scientists supplement
| this by saying that mans vitality Is at
| its best between 10 and o'clock in the
| day. This period includes the time of
| the maximum height of the diurnal pres
| sure wave.
Effect on Animals.
Now 1t will not be surprising that de
| crease In pressure before storm amount
| ing sometimes TO half n ton with hu-
man being and proportionately more
often with animals, should affect the sen
sibility Of body, and cause, especially
animals. which live closer to nature than
man, to show signs of restless behavior.
The latter Is usually attributed TO :hc
animals instinct that tells of approaching
bad weather. Birds fly nearer the ground
| and bees swarm out and Immediately re-
turn to their hives before a storm. They
do but it Is IA matter of convenience To
them. Birds soar usually as high as con-
| ditions will permit and when the air pres
sure decreases before n storm they re-
main near the ground where the air Is
stll densest, and bees find flying hard
work, anyway, and stay at home
! As the temperature rises with the adj
vance of a storm so the capacity of tile
air for moisture increases. and increas-
| ing humidity acts on an organism simt-
lar to decreasing pressuse. and often BON
act together. There is man vino pre-
diets rain when the salt box gets moist
| and cloggy, but opposed to this view Is
| the man who always feels dry ON the
night before the rain. Both are right To
some extent Humidity Increases before
the rain. but often only a few hours be-
fore, and in the winter the day before the
storm is in many instances the dryest oi
| the season.
Weather Toys.
Mention may be made here of those lit
tie toys often used as weather prophets
| and consisting of n small wooden hood
| with two doors. From one Of the doors
comes out a lady with a paraso to ind-
cate fair weather and the other a man
| with an umbrella to give warning of com
ing rain. These toys may be constructed
on two principles. Either the two figures
may be set in motion by the expansion or
| contraction of tension. hair or some
plant tissue, while the latter absorb
" <iature or dry out The other method
Z, 60 connect the figures by means of a
syssem of levers to a small thin metal
box from which the air has been eX-
hausted, with changes in the air pressure
the tention on the box Is decreased OF
increased. as the case may be. and the
levers and with them the figures are sci
in motion.
On the last principle the aneroid baron
eter is constructed, the clock shaped in
struments with fair, changeable and rai
| marked around the circumference OF the
dial. But all these weather Indicators
regulated by single element make them
useless for the greater portion of the
year While humidity Increases as a rule
but a short time before rain begins. IT
remains high usually all through the sum
mer season, and those who have watched