The morning times., 1895-10-03
GOLDEN GATE TO ClPES
Great AlI-Around-the World Sur
yey Finished.
EARTH'S SHAPE DETERMINED
Most Important Contribution Ever
Made by Government to Science.
Greatest Geodetic Line Ever Meas
ured In the WOrId-Present Lines
of Longitude Not Accurate.

The scientific measurement by the
United States Coast and Geodctic Survey
OF the distance from the Golden Gate of San
Francisco, cal, to the mouth OF the Chcsa-
peakc along the thirt y-ninth parallel, has
been completed.
The news that the last line of the last
triangle had been taken in this great work
has been received by Gen. Duffieid the
superintendent of the survey, in q dispatch
from Mr. William Einbeck, who has been
in charge of the undertaking since It's in
ception in SS3.
Every scientist in the world has been
waiting anxiously for this news. Its I'M
portance may be judged from the fact
that upon this east and west line de-
pcnds the determination OF the precise
shape OF the earth and the accurate la wing
OF lines of longitude instead of the APP
proximate ones that are now in use. This
line viii be the basis for II revision OF all as
Economical work in which accuracy is
desired.
Gen. Duffield sa i'll yesterday:
Twelve years ago a party of surveyors
began measuring trianglcs al the same
time at each siuc of The continent. One
started from the mouth OF the Chesapeake
Baya worked westward; the other sta rted
at the Golden Gate, in California, and came
eastward.
THEY MET HALF WAY.
They met among the Colorado mount aims
at a designated spot on saturday a week
ago, and the gcodetic survey was concluded.
As soon as the pariy reached Il telcgrap pbic
station they sent me- the news which the
International Geodctic Asscciai ion, now
in session in Europe, has teen awaiting 50
anxiousIy.
'It viii take yet a year in all prob
ability, to make the computat ions from
the survey and such vcrifIcatiohs or por-
tons of the work as may bc necessary.
The figures have to he reduced to the
mean sea level. When This is done we
Will be able TO determine the distance
between San Francisco and the mouth
OF Chesapeake Bay within few yards
OF absolute accuracy.
The work has cost something over
Sl5O,O00. one of its most practical adj
vantages Will be that il viii enable the
determination OF distances between cit
les and the heights above the sea level
OF all points along the thirt y-nIth par
allel. Its scientific advantages are much
greater. In fact, this work may be taken
as the greatest contribution ever made TO
science by a government.
OBJECT OF THE SURVEY.
"The chief objec; OF the work is TO
determine the precise figure OF the earth.
1t bas already been determined by north
and south lines. but This one which we
have Just completed is the only one of any
extent running east and west.
There are two or three of the north and
south lines. Russia has the longest meridian
line ever run, going from the Black Sea up
To the northern limits other territory.
There is one in India run by England that
is next in length. while the third was run
by England and France i'll conjunction
from the most northern point of Scotland
down TO the Ialearc Islands. From these
lines the shape of the earth has been de-
tern,ined north and south, while II has been
necessary, i'll order to ascertain the exact
shape, toruna sinlila T line eastand west.
THE United States is the onl y country that
has enough territory east and west to ac-
conplish this, which VIII he the greatest
geodetic line ever measured in the world.
''MathematIcia have figured out what
the shape of the earth ought to b.. They
have worked ON the basis OF the rth in a
molten condition. Knowing the number OF
revolutions and the centrifugal force, they
could calculate about what the earth's
figure should be. But the earth cooled more
quickly at the poles than at the equator,
and did not take the shape that the maihe-
nlaticiauS had figured on. In order To de-
termine what its actual shape was. there
fore, perfect triangulated survey was
necessary.
ABSOLUTE ACCURACY NEEDED.
while the present lines OF longitude are
close enough for tine ordinary use of sailors,
they are not sufficiently accurate for scien-
tiric work. To determine any astronomical
observation it is necessary to have a vertical
line in order to obtain the zenith. That
vertical line is at right angles to the
tangent to the curve OF the earth al that
point
"The plumb-line does not give a true yer
teal line. 1t is affected by outside influ-
ences, at the scashore by the fact that the
lighter water is on one side of il and the
heavier land on the other. and i'll the in
terror OF the country by the emountainmasses
on the one side and the plains on the
other.
THE correction of plumb-line there
fore is one of the most difficult tasks in
physics, instead of the simplest, as an or,li-
nary observer might think. With this
transcontinental geodetic work completed,
We will be able to supply that vertical
line. so necessary to all exact astronomical
work.
"The whole scientific world will owe n
debt of gratitude to the United States Gov,
ernment for the energy and skill with which
it has accomplished this great and import