The sun. [volume] (New York [N.Y.]) 1833-1916, 1896-11-02
MEASURING THE EARTH.
TryinG to Determine che Exact Shape OF
the Planet on which We Live.
From tho Denpcr Republican,

From tho Denver Republican.
An arc 5000 miles in length. which has
been in process of measurement by trianEula-
ton for q period OF over thirty years, showing
the curvature Of tho earth's surface on this
hemisphere. was completed by the United
States Coast and Geodetio Survey carly this
month. Although IL is the most gigantic
feat of geodetic surveying ever accomplished
anywhere In the world, no public announce
ment of It's completion has heretofore been
made.
The enterprise was inaugurated by Presi-
dent Jefferson in 1907. but no active progress
In pushing 1t was recorded for many years
later. Since 1874 several parties Of civil en-
glneers have been at work almost steadily be-
tween the Atlantic and Pacific coasts making
the trlangulations for the big arc, under the
direct supervision OF the different Coast and
Geodetic Survey superintendent. These earth
measurers worked in general line toward one
another from both siaes OF the continent.
lines from which the closing CALCULATIONS
have been made were verified. One was
IN his Sal. L LAKE sss valley. Utah. "NN 'I'
WIFI Ens1 ESsIn, p; M 4 Mslf Eia;b @ho on SoG 1bs saIt
Lake Valley base line. is now at the Brown
Palace Hotel. He mas just returned from
Utah. and is on his way 70 Washington to
In Kansas were taken under the direction OF
Engineer GrainRsr.
1t is extremely difficult to give in an inter
view anything like a comprehensive and In
teiliEible account of the work. the United
States coast and Geodetic Survey has lust com,
explained Engineer Welker yesterday. The
general purl ose In measuring. an arc across
the true curvature Of the earth on this hemis-
phcre. An accurate survey, something that
was never before reached. is also desired. Sur
yeys are generally made on the basis that the
surface OF the earth IL nat.
This country is cooperating with all the
other civilized countries for the common pur-
pose OF getting n new figure Of the earth estao-
iished. This figure will be an approximately
general use. Bessei's ellipsoid, the first figure
q the earth used BY scientists. was established
from dtta collected by the Germs9s. The next
lished. l think. by Clarke. an EnGllshman.
In 1874 an international agreement was
reached among the civilized nations to take
measurements for another ellipsoid. one that
Will be practically true. Every Government
face OF the globe. The arc in this country il
the longest measured by any one nation. 1t 10
All surveys in this country arc to be cor
Tected by the hTs measured Tsd o ont Ir1m s tine Az.
not allow for tho curvature OF the earth. In
count to county. allowing for 4 nat surface.
and. the consequence Is that the surveys thus
There have been a largo number of en-
cheering parties employed on the a American arc
ron jSins sim ln $! Salt tina Isle T vaileg last mlm snmms wh Sas
recently had general charge on the triangula-
ton operations from the Pacific coast 70 the
up the work on the Kansas base line.
Two years ago the connections between the
made at Noun Ebert and Ouray. | was up
there then. using the helfoRraph In getting the
measurements among the mountains. By this
system of sun flashing much better work can
be done In a mountainous country than on tho
plains. as we get longer lines.
ured conformity by England. Germany. ana
Russia. These countries combined on one arc,
and France and Spain on another. The Eng
lish have also done n good deal of trianRuln-
ton measuring In India. AS ] said before. all
the important nations have been engaged in
1T will probably be a year before the cal
c%ulations are all completed and a true figure
try Will be combined with aIi:the others estab-
lished over the globe, and the mean curvature
expected. that the trianeulation c1leuiations,
combined with the use OF the pendulum. will
give us the length OF the earth,s diameter; to
ence of fifty feet from the exact diameter:
I'm taking measurements hero we first
miles In length. This is our base line. From
this base the, engineers then spread out with
ffir po n of and s9H Tn mii.s. F 70 as those fo eed aal
ures we spread out into lines running from 100
to 100 miles In length, using the ordinary
In q, INJECTION with the work OF triangula-
ton Just finished. another party of coast and
geodetic survey engineers havo been engaged
In running q line OF levels across tn" American
continent. This latter is being done, for tho
purpose Of accurately establishing attitudes.
These had heretofore been fixed chiefly by
the railroad companies. The line of levels
will run from Sandy Hook. New York, to San
Francisco. 1t took uvor thirty years work in
Pacific 70 get true sea levels as a preliminary
10 tho altitude survey. The line OF levels. has
reached Kansas from the Now York end, whore
operations on II were suspended about two
months ago.