Evening star. [volume] (Washington, D.C.) 1854-1972, 1954-03-08
Eclipse Moy Provide
Atlantic Measurements
Distance From New World
To Old Not Exactly Set
By Thomas R. Henry

The distance between North America
and Europe may be measured with an
accuracy of fractions of an inch dur
ing the total eclipse Of the sun by the
moon on June 80.
This will be possible through meas
uring the instants of first and last
contact Of the moons shadow with the
solar disk at various points during the
approximately two and three quarter
hours on the 5000 mile path from
Nebraska to Pakistan.
It will be the most comprehensive
study Of solar eclipse In history. ac-
cording to an announcement from
Georgetown University whose astron-
omers, under contract with the Air
Force Research Command, will take
part in the program. Other co-operat-
ing agencies include the American
Geographical Society, Ohio State Uni
verSity and the University of Chicago.
There will be great number of in
dependent Investigations with compli-
Gated instruments set up at places
like Knob Lake, Ontario, and the Okak
Islands off the coast Of Labrador.
There will not be another eclipse cross
ing North America and Europe before
2151. says the Georgetown announce
ment.
Eclipse Starts in Nebraska.
The June eclipse will start in Ne
braska at sunrise and proceed through
eastern Canada, Labrador southern
Greenland, Iceland, the Farce and Shet-
land Islands, Southern Norway and
sweden, Russia, Iran. Afganistan and
PakiStan. Along this path four major
and eight minor observing stations will
be set up, the latter along the edges of
the 80-mile shadow.
The Georgetown station, under the
direction of Rev. Francis j. Hayden,
will be in Iran.
1t is expected, also, that Russian
astronomers will make extensive OBJ
serVationS of the path through Soviet
territory. but their plans have not been
announced.
To Use Three Methods.
Three methods of time observation
will be used. One will photograph di-
rectly the creScents of the sun as the
moon passes between it and the earth.
Another will show the reversed Spec
trum as the moon passes. The third
Will measure the decreasing light in
tenslty as the moon shuts out the sun.
Because the speed of the moons
shadow and the precise time of it's
locations are known, distances can be
computed very accurately through the
use of these three methods
With new tables recently completed
by Yale scientists, the moon is now
recognized as the most accurate of all
timekeepers, and theoretically it should
be possible to measure intervals of a
few billionths of second. Thus it
will be possible to compute the dis
lance between any two points along
the eclipse path.
May Reveal Land Mass Drift.
Precise distance between North
America and Europe is of considerable
theoretical Importance. There is some
reason to believe that the two great
land masses may be drifting away from
each other. or towards each other, as
is assumed to have happened in the
past. The amount of drift is so small,
however, that it can be computed only
by radio transmission intervals meas
ured over periods of several years, and
results to date have been quite indie
terminate. This is due in part to in
adequate knowledge of precise dis
tanceS.
All the measurements along the path
will require split-second timing and
all the instruments must be in alb
solute readiness to go into action. The
most intensive work at each site must
be completed in a period of little more
than three minutes, which includes the
few moments before, during and after
the total eclipse phases.