Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-11-23

the work progresses, to inquire of the
Coast and Geodetic Survey of the
chances OF earthquake ct some given
place. Likewise, insurance companies
may base their rates on the relative
probability of disturbance.
Foreknowledge Of the probability Of
earthquake visitation need not discour.
age occupation. The cities Of Toxic and
Yokohama, Tor example, know perfect
ly well that they are not immune from
further seismic disturbances and, pre-
sumably, never can be, situated as they
are on the edge of the unplumhed
Japanese Deep In the Pacific Ocean
toward which the land Is disposed 10
slip. Indeed, several minor tremors are
felt every day. There have been some
10000 Quakes since the great one of
1928. But, forewarned. the designers
OF construction in these cities have 90
built their various works as to resist the
tremors.
Air and Coast Maps Demanded.
The demand for the Surveys airway
maps steadily increases. The Survey
makes what are known as strip maps.
These cover In detail certain strips Of
the country over which an air route
proceeds. The aviator, not wishing 70
be encountered with large map of the
whole country and also wishing a map
drawn to a fairly generous scale may
obtain one showing the characteristics
OF given strip of country. Thus, he
may OBTAIN narrow strip map Of the
country between New York and Rich
mond. Covering hundreds of miles in
length, the map will show q width Of
only some 20 miles. Such strips are
obtainable for all principal air routes In
all sections of the United States.
The general coast survey work Of the
organization Is proceeding on an ever
enlarged basis. Included In the work
OF the Coast and Geodetic Survey not
only Is the showing of contours of
coast lines, bays and inletS and the like,
but depths of water as we'll and these
data become increasingly important as
the size OF ships enlarges and water
trat1c becomes more congested
The maps of the Survey show the
depth in feet and fathoms of every
haroor,, bay, bite, sound, inlet and
channel These surveys are carried
well out TO sea to indicate how the
beach shelves of. Bars and banks and
shoals are indicated offshore. In the
case Of the Georges Bank, for example.
where the New England fishing fleets
ply and which Is crossed by the trans
atlantic steamship lanes. the survey IL
carried 200 miles of the coast.
The Survey also Is engaged in per-
fecting q basic survey of the entire
country, more than 100000 square
miles. This Is to be q master map and
every other survey must conform to
its basic locations Throughout the en-
tire country thousands of monuments
are being placed showing not only pre-.
else lacation by latitude and longitude,
but elevation above sea level. Bench
marks are placed on structures prom
Using permanence and can be consulted
ny local surveyors, who may take their
departures thence assured of an ire
fragable certainty.
AS well as supplying maps for use in
navigation OF the air, the Survey also
Is employing airplanes in making of
surveys, finding the birds-eye exanii1a.
ton OF both land and water surfaces a
great aid in expediting the work.
THESE ultra-modern activities Of the
Coast and Geodetic Survey represent a
lar cry from the simple coastal meas
urements which were made when James
A. MON. Whistler, afterward destined
TO become one of the worlds most ia
nous artists, worked here at Washing
ton as an engraver Of maps for the or
ganlzation. The vignetfes Of bits Of
coastline, rocky cliffs and The like with
which ne decorated the ma,gins Of his
maps stlIl are preserved.