Evening star., 1909-05-02

a modest exterior, three stories in front.
but stretching far back in the direction
of the Potomac. The archives Sc
cured in 4 fireproof building adjoining
property to the amount of millions Of dol
lars. including original sheets OF hydroG
raphy and topography. original engraved
plates of charts from the foundation of
the survey. ctc.-while on the other hand
is a small building devoted TO the cleo
trotyping processes. The main edifce
looms up in the rear some five six
stories. The offices are arranged simply
for work and offer scanty attractions for
sightseers, and the records. though i'm all
libraries. are too vou'ninous and OF too
much weight for popular reading. Hence
the great American public. to whom every
detail of this work is now of vital inter
est, are possessed with me4ger facilities
for an intelligent comprehension of its
magnitude and scope.
a.
Discoveries of the most wonderful char
acter and invested with all the charm
of novelty are constantly growing out OF
the various observations involved. or
these studies OF magnetism and Of sea
currents have produced some of the most
striking results. The variations of the
compass can now be predicted for any
hour in any place in the United States.
This strange triumph has been accom-
plished through a series of careful OBJ
servationS of different stations in every
part of the country and compared with
the precise observations of former years.
Such variations are much greater for diff
ferent localities than is commonly imag
ined. Want of knowledge in this matter
has caused endless blunders in land sur
veys. Some of our maps misrepresented
the site Of certain inland cities by nearly
three miles. These new measurements
are of great service In the projection of
a,,l ,1r tt,f, rNf
the aid they afford In the correction of
erroneous maps of the coast. Charts
used twenty years ago by coasting yes
sells in their trips to various ports have
been found to contain discrepancies of
longitude often as much as nine miles,
caused through local variation of the
compass. striking triumph in magnetic
observation has just recently been achiev-
ed by the survey. This is the determina-
ton, from the records of magnetic in
etruments at different stations Of the
place at which an earthquake has oc-
Cured. Thus the late disaster in Sicily
was located by the surveys records with
out difficulty and short time after its
occurrence by telegraphic communication.
The experts OF the survey knew of this
disaster. the place where 1t occurred and
it's probable extent before the general
public were informed by The press. Sim
gular to relate. this result is not possible
in case of volcanic disturbance, which
makes a practically instantaneous record
upon the recording instrument, no mat
ter how far distant from the scene of the
disturbance the latter are located. This
was the case in the Mount Pelee eruption.
the record of which was flashed upon the
surveys instruments at the very moment
1t occurred.
The original design of the survey TO
furnish accurate knowledge of the coast
of the United States for mariners has
been more than fulfilled as far as the
work has progressed. But this is only
one of the phases of the work. The geo