Evening star. [volume] (Washington, D.C.) 1854-1972, 1927-12-18
Adventure Is Found in Search for Raw Material of Geography

! approximately INTO lhelF proper posi
/ tons.
/ GINCE America was tied on to the
I ~ rest Of the world by the establish
ment of true longitude on this side
OF the Atlantic. a careful network of
measurements has been extended by
the Coast and Geodetic Survey East
and West. North and South over the
country. This has been of inestimable
value to mapmakers. enabling them tn
represent places in their true posi-
tons. 1t has in a measure been IN
dependent of astronomical longitude
positions while in progress. and has
been in effect as if most accurate
vardstick had been laboriously applied
end to end across country.
The measurements have been much
more accurate, however. than if they
had been made with yardsticks or steel
tapes, leaving room for errors at the
many Jennings of the ends. They have
been made by the continued measure
ment of one base line until accuracy
is insured and then by the careful
reading of angles from its ends to
other stations and the calculation OF
the distances by trigonometry.
This system of triangulation, as IT
is called. is first laid down on the sur
face of the ground. But the distances
desired are at sea level. The idea IS
that a'ong line connecting the Allan
tiCe and the Pacific, for instance.
canal should be dug and the distance
measured along the water surface
from ocean to ocean. Geodetic survey.
Ors have no magic steam ShoVels at
their call to dig their canals, but
from the surface information they
gather they burrow unerringly with
trigonometry and higher mathematics
RI
level basis. Though the surveyors
have only skinned the surface, their
triangulation system has been in effect
laid down hundreds and in some cases
thousands of feet underground.
The longitudes of places obtained by
Geographic and astronomical means
do not exactly agree with their posi-
tons determined by triangulatiOn. So
long as the vertical is detected 1t is
inevitable that such discrepancies
shall occur. Recognizing this condi-
ton, the Coast and Geodetic Survey,
after it had extended its triangulation
across country. employed intricate
mathematical processes and in effect
shifted the rigid network of its meas
urements about very slight distances
until the errors in longitude and iati-
tude of all the various stations were
brought to the least possible quantity.
Then the network was "pegged down.,
so to speak, to serve for all time as the
basic map-making and surveying skel-
eton of the country. AS dominant
point, the kingpin of the whole sys-
tenn, station was established in north
central Kansas, at Meade's ranch. AL
though this point is to the multitude
of lines and boundaries in the United
States what Greenwich is to world
longitude, it lies far from the beaten
path, in a cultivated field, where per-
haps not one in a hundred thousand
Americans will ever see it.
x X X X
THIS geodetic capital of America
Il the primary station" geodetsts
call it-consists of a mass of masonry
Of about the size and height of din
ner table. Into its surface is set a
metal plate on which cross mark Is
engraved. On the tiny point where
the lines cross hangs the latitude and
longitude Of sixth of the worlds
land surface, for both Canada and
Mexico have adopted this point and its
supporting system as the North
American datum"
Kansas is nearly quarter of mile
wider than was originally intended be-
cause the pegged-out boundaries, sup
posedly along even degrees of latitude.
are too far north in the case Of the
northern boundary and too far south
in the case of the southern.
Colorado's western line Is nearly
half mile farther west than was pro-
vided for in the law defining it's boun-
diaries. A discrepancy of the same
size in the southern line was made the
subject OF a suit by New Mexico be-
fore the United States Supreme Court.
Montana's east boundary is sup
posed to be in a straight line along
the twenty seventh meridian west
from Washington. In reality it is
two-thirds of a mile farther east In
places than it should have been-a
large enough amount to be apparent
on most maps, and its direction some
times DIVORCES from true north by
more than tenth of a degree.
The fact that these State bounda-
ries were not located on the parallel
or meridian named in the law defin-
ing their constitutional limits does
not affect their legal status. After
| boundary survey is once made, ac-
Cepted by the States concerned, and
approved by Congress. the marks
established become the legal boun-
| Diary. The boundaries of the States
were in most cases laid down by the
best methods available at the time and
the errors inherent in astronomical To-
cations were unavoidab BILE.
OF course local surveys always are
in progress. The precise triangula-
ton surveys made by the Coast and
Geodetic Survey provide starting
points for these surveys. The sur
vey's markers, denoting either latitude
and longitude, or heights above sea
level. are to the surveyor what its
navigation charts and tide tables are
to the mariner.
There is a fascinating story, too
IN he cd in he oil
cate instruments the survey has de
vised and employs 1t uses a pendu-
lum so mounted that it will keep go
ing for l. hours; in its magnetic work
it has machinery so finely adjusted
that an automobile passing IS or 100
feet away may ruin a set of observa-
tons
The survey has just completed a
super-theodolite- theodolite being n
glorified surveyors ansit-which is
the most complete and accurate instru
ment of its kind yet devised 1t has
sights of fused quartz substance
which transmits light around cor
ners." which long has been a scen
lists plaything. Another practical
use had previously been found for
fused quartz; it is employed in certain
delicate surgical Instruments
THESE are only few of the instru
ments and instrumentalities, from
steamships to magnet needles, which
the survey employs in it's complicated
work of finding the simple facts
which enable our ships to sail, help
locate our railroads and highways and
bridges, and make our realty deeds
valid.
Curious Gforo6e