The Dickinson press., 1890-02-08
FROM HIGH TOWERS.
How They Will Be Important Assista
in M~etooroloEico Inuuirv.

How They Will Be Important Assistants
in Meteorological Inquiry.
London is to have a larger edition Of
the Eifel tower. It will be 1900 feet
nigh, and will enable scientific men to
make important observations not posi-
BILE on the earth's surface.
The proposed tower would allow of an
inquiry into the atmospheric conditions
up to 1900 feet. Instruments for meas
uring the heat of the suns rays, such as
black bulb thermometers in vacuo, and
actinometers, disposed at the top and
bottom Of the tower, would also give
very interesting readings, tho instru.
ments at the highest station probably
showing an excess of the suns heat over
the other, because of the atmospheric
humidity intervening between the earth's
immediate surface and an altitude of
1900 feet.
Thermometers disposed at various
heights and properly screened from
radiation would show the temperature of
the atmosphere at different levels; the
air would probably be found cooler on
rising higher and higher, giving this Gu
rious resultant tho sun would be
warmer at the top than at the bottom;
but, in tho absence of tho sun, tho air
would be colder at the top. At night
the distribution of the temperature in
the atmosphere is known to be the re-
verse of the daytime. On a fine, clear
night the temperature will be found
higher at 1000 feet than it is on the
earth, whilc on a cloudy night it will be
much the same at both stations; but we
have much to learn of tho laws of ter
restial radiation, and the proposed tower
would be very useful in that respect.
Of course an observer would not be
expected to race day and night up and
down a tower 1900 feet high, to make
observations and read thermometers;
this would be too great, and indeed an
unnecessary devotion to science. The
whole thing can be done from below in a
comfortable building by means of Sic
mems electric thermometers. Such an
instrument has been used for some time,
and is now at work at the Lincoln cathc-
dral, giving correct thermometer read
ing on the earth's surface from a height
of 270 feet. Besides observations for
temperature at various attitudes, the
state of humidity of the atmosphere, a
condition greatly concerned in the forma-
ton of fogs, could be readily examined,
dry and wet bulb thermometers disposed
at various heights and in electrical con-
nection with the station below would
yield interesting observations, and assist
materially in conjunction with the ba-
rometer in ~forecasting the weather.
The force and direction of the winds
at various attitudes are subjects for me
teorological inquiry of much interest
and Importance; there are eddies in the
atmosphere, spiral and upward currents,
of which little is known, and a tower
such as that nov contemplated would
allow of very interesting observations to
DO made on winds. We may also ven
ture to suggest that the information thus
obtained would have an important prac-
teal bearing in an engineering point of
view, as showing the strength of tho
wind buildings may have to Withstand
at great heights. The measurement of
rainfall, made simultaneously at 1900
feet and on the ground, would add to our
knowledge of the laws of rainfall; il!
would be found that less rain falls at the
top than at the bottom. The connection
of this phenomenon with atmospheric
humidity and temperature would be
very interesting to investigate.
"Finally, earth %trenlors, the forerun-
ners of earthquakes, would be felt at the
summit of a high tower much more
readily than in contact with the earth,
and earthquakes might be expected to
produce greatly magnified effects at such
an elevation; hence a seismometer
would find a fitting place at the top of
the proposed building. A great deal
might be added on this subject. We have
not touched on the astronomical uses of
a very high towerfrom the greater clear
ness of the atmosphere at such an alti-
tude. There are also other pointso Of physi-
illogical interest that could have been
dwelt upon, such as the influence of an
altitude of 1900 feet on respiration, or
on the v system. 1t might be re-
marked that there would be little fear of
feeling giddy when looking down from a
tower of such height, although tho view
over a p~recipice of 1900 feet would not
be unlikely to produce a most unpleas-
ant sensation.-British Medical Journal.