Iowa state bystander. [volume] (Des Moines, Iowa) 1894-1916, 1913-04-11
KILLED BY A MORO|HE|GHT OF CLOUDS
instruments for Measuring EIe.
walton and Movement.
Workings Of the Besson Nephosceea
an ingenious Device for Extract.
= Ing Secrets From the Skies
Motion Of vapor Masses.

Motion OF vapor Masses.
How many people that one meet,
in the course Of the day have ever
observed carefully the motion of tha
clouds that are SO uncomfortable
prevalent this summer? Or, II asked
about the matter would not most Of
them say that the clouds move in thu
same directions as the wind at the
surface of the earth? Perhaps ons
more observant than the rest would
recollect that thunder clouds have a
way of coming up against the wind"
and he might even add that he had
observed high cloud moving in a
direction different from one lower
down. Again. would not most people
say that the mares TALL" or, as the
meteorologist would call them, the
cirrus clouds. never move at all, or, at
least, only very slowly. and that low
clouds move more quickly than the
cirrus?
interchangeable word which has
lost its original meaning to such an
extent that it now denotes simply
the science of the atmosphere" and
includes, therefore, the study Of eli.
mate and weather. including clouds
and their motions-has extended its
operations within recent years very
notable by considering more definitely
the conditions prevailing in all the
layers Of the atmosphere and not
merely in the surface-layer 1t is
true that clouds have been observed
and their motions studied scientifcal-
ly for long time, but since instru-
ments carried by kites and balloons
have taught us so much about the
temperature conditions in the air up
to heights. of sixteen miles and more,
a renewed interest has been taken in
the forms and motions of clouds, for
the motion Of cloud usually (but
not always) indicates also that Of the
air in which 1t is floating.
One of the best instruments for OBJ.
serving the motion of cloud is the
Besson nephoscope. The instrument
consists simply of an inverted harrow
or comb fixed horizontally at the end
OF a vertical rod which Is mounted
in bearings carried by an upright
post, so that the rod can be rotated
Near the bottom Of the bar is
crosspiece, to the ends OF which two
strings pass to the hands of the Oh.
server, while underneath is circle
graduated with the points Of the COM
pass. The method of observation is
to select the cloud to be observed.
stand on the side Of the post opposite
the cloud, and with the strings rotate
the upright rod and therefore the
comb until the cloud appears to pass
along the points of the comb It will
be necessary to approach or recede
from the pole until this appears to
take place. Then, standing STILL note
the time the cloud takes to move
from one point to the next. Finally,
note the orientation Of the comb by
means of the graduated circle at the
bottom Of the rod. This gives at
once the direction of motion of the
clouds while the apparent velocity o!
the cloud along the comb is meas
ur1ng of the rate at which the cloud
Is moving, expressed in terms of the
height of the cloud. For example, II
two clouds at heights of 5000 feet
and 5000 feet appear to be moving at
the same rate along the comb then
the latter is actually moving twice as
fast as the former.
The height of q cloud is not so
easily determined. Usually two OBJ
servers, each provided with theo-
dolite, are required. but sometimes
one theodolite can be made to suffice.
This instrument has it's telescope re-
moved and two parallel plates OF
glass arranged in place of the tele'
scope. Then two images Of the cloud
one formed by reflection In the
glass, the other by reflection in a.
small sheet of water lying on the
ground below, are made to coincide
by rotating the plates of glass. The
position of the plates SO determined
is read of on the graduated circle
shown near the observers hand. The
height can then be computed mathe
matically.
AS a result of these observations, II
is found that, In general, If one stands
with, ones back to the wind, low
clouds move, In about the same d.
rection as the surface air, while the
higher clouds travel nearly in the
same direction, but have motion
from left to right which becomes
more pronounced as the height In.
creases. High clouds usually traVei
much more quickly than low Ones
although apparently they do not.
The highest clouds rarely exceed .
hight of six miles.
Suicide That In Glorious H.