Evening star., 1934-04-26
BY THOMAS r. HENRY. ,


The map of the world is sticking
together.
This is indicated by preliminary re-
suits of the world longitude observing
program carried out last Fall, which
were reported at the opening sessions
of the American Geophysical Union
here today. 1t was undertaken as an
international project to check up on
the hypothesis that the continents
are drifting apart like RATS in the
underlying sea of mobile rock upon
which they float" esv.-
The American observations were
taken at definitely determined points
at Annapolis and Honolulu and for
three months radio signals were ex-
tance at precisely known speed,
that of light, it could be determined
whether Annapolis and Honolulu were
farther apart than when the last OBJ
servations- were taken in 1926.
Error Absorbs Difference.
The mean of all the hundreds of
observations, it was reported by Lieut..
j. P. Lushene of the Coast and Geo
detic Survey, who was in charge OF
the Honolulu station, was only about
seven-thousandths of a second diff
ferent from the mean of the 1926
observations. This was so small as to
be negligible in view of the probable
error which practically absorbed it.
If there was anything like the con-
tinental drift which has been assumed
from other measurements, the differ
ence cumulative over eight years
would have been appreciable.
The idea that the continents are
drifting apart, Lieut.. -Lushene ex-
planned, arose first from the fact the
Atlantic coast lines of Africa and
South America would fit into each
other like pieces of a jig-saw puzzle,
leading to the suspicion that they
might once have been together. There
was less apparent conformity of the
same sort between the Atlantic coasts
of North America and Europe.
Drift Hinted by Maps.
The idea of this continental drift
was supported further by measure
ments based on the position of the
moon, which showed an increase of l8
meters year for nearly century be-
tween Greenland and North Europe.
Additional evidence was obtained
from the time of transmitting cable
signals. Both these methods. how
ever, were of questionable validity.
The Coast and Geodetic Survey re-
port showed the continental drift
theory probably is not true, SO far as
concerns North America and Homo
lulu. The observations will be fitted
into a general picture obtained from
similar work in other major stations
maintained throughout the world
But the direction north" so far
as it is shown by the compass, is
changing. it was reported by A. j.
McNeish of the Terrestrial Magnetism
Laboratory OF the Carnegie Institu-
ton of Washington. 1t is not chang
ing, of course, SO far as observations
based on the Pole star are concerned.
Change Varies in Cycle.
If a man walked directly north
from Washington, Mr.. McNeish re-
ported. his compass would take him
over the Canadian line today about
10 miles east of the point where he
would have crossed 80 years ago. This
is due to fluctuations in the earth's
magnetic field, which seem to vary
With the 11-year sunspot cycle.
The earth weighing experiment at
the Bureau of Standards, which has
been In progress for the last 10 years,
is leading to a lower value Of gravity
than that given by the textbooks, it
was reported by DR.. Paul Heyl of the
Bureau staff. The earth doesn't
weigh, by a few odd tons, so much as
was thought.
The results Of the Bureau of Stand
ards experiment still are very tenta-
tive. They have shown, however, that
the value of gravity reached by meas
urements at the Potsdam station in
Germany 80 years ago. and which
were supposed to represent about the
nearest thing to absolute precision
Imaginable, was seriously in error.
The Potsdam value, DR.. Heyl said,
generally has been accepted without
reading the material on which it was
based and when this is once examined
it shows that the German physicists
were by no means so careful and
thorough as they have been credited
with being.
ThundercIOuds Explained.
The thundercloud is a gigantic gen.
Grating plant. Every year a billion
kilowatts of electric energy are gen.
Grated in such clouds over the whole
earth and less than a tenth of it is
manifested in visible lightning flashes,
DR.. B. F. j. Schonland of Cape Town,
South Africa. told the American Me-
neurological Society yesterday.
AS a result of his own experiments,
DR.. Schonland turned the generally
accepted model of the thundercloud
upside down. Lightning discharges
are due to the fact that one side of
such a cloud builds up a positive
electrical charge, while the other side
builds up negative one. From theory
it has been supposed that the top was
negative and the base positive, the
negative charge being carried upward
by rising warm air carrying negative
charged fragments of water droplets.
DR.. Schonland's observations show
exactly the reverse must be true, rem
.dering an explanation of the phe-
nomenon of lightning more difficult
than ever. Nine-tenths of the lightning,
he pointed out, is expended within the
cloud and is never seen. A lightning
fash. he pointed out, builds up a
power of about $4,000 volts an inch,
potentially nearly 2O0,00OOO volts for
a path a mile high.
Controversy Renewed.
The old controversy of the Weather
Bureau with proponents of weather
cycles was renewed in paper by j. B.
Kincer, head of the Division of China
tology, who analyzed the alleged IL,
% and 35 year cycles on the basis of
the bureaus actual observations for
not be two sets of tracks on Four
teenth street between H street and
New York avenue. But the traffic in
this knot is so heavy that any change
must have very long and careful
study Among nlans under consider.