The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1902-01-05
NEEDLE NOT ALWAYS TRUE.
Compasses do Not Invariably Indi-
cate the Right Direction.
Helena independently

t1eleQa independently
AS true as the needle to the pole"
is a phrase that requires modification
in these days, for, if Biographies are to
be believed, it is not always true. Ex-
periments are being made at the United
States revenue cutter service station,
Curtis bay, in the study of magnetic
compass variations, a matter the gov
ernment is also investigating at Chel-
tenham, Nd; in Alaska, in Honolulu
and in Kansas.
In Baltimore the needle pointed 6 de-
grees and minutes west in 1870, and
in 1902 was only 80 minutes west. A
street mile long laid out by the COM
pass in that city in 1870 would have had
its north terminus 504 feet too far west
in 1902. 1t is related that a magnetic
party. while establishing a meridian
line for the use of surveyors at Ches-
tertown, Nd, the county seat of Kent,
found that the main street ran nearly
magnetically northwest and southeast.
Assuming that the street had been laid
out to run exactly so. it appeared from
old magnetic data that the town must
/ have been laid out in the early part
/ Of the eighteenth century. Upon look
/ ing up the records the assumption was
/ found 10 be correct. The town had
] been laid out in 1902.
/ The historic Mason & Dixon's line
was fortunately run, in 1886, by the
| stars. and not by the needle. If in the
/ year 1900 it had been run so as to be
magnetically east and west, beginning
! "a the eastern end, and supposing that
/ the surveyor would not have encoun-
! tered any areas of peculiar local dis
/ tUrbances, the boundary line would
have thrown Emmitsburg into Pennsyl-
vania. making a deviation of two and
one-half miles But were the line run
/ under the same conditions today it
would drop nineteen miles to the south,
which would surrender the richer pOr-
I ton of Allegheny and Garrett counties
to Pennsylvania and would cut Mary
lands western boundary line in two
This illustrates the inaccuracy of sur
veying by the uncorrected needle.
1t has beer popularity explained for
years that the needle pointed to a mag
netic pole which has been located at a
spot northwest of Hudson bay or Boo
thi5 Felix, but recently scientists have
not been so sure of the fixity of this
magnetic pole. The fluctuations in the
needle from time to time through sec
ular periods, to say nothing of the
slight variations at different hours of
the day, indicate that many elements
enter into the reckoning, and science
mas by no means settled the cause and
meaning Of them ALL It is easy TO
accoUnC for local eccentricities OF the
needle by the presence Of deposits of
iron or other metals attracting or re-
peiling the needle. but the theory IN
DERIVING the whole thing still remains
much in the dark.
Just now the work Of this govern
ment and of most of the others CO.
operating with il is decidedIv. practt-
cal. From a large number of observa-
tons IL is expected that the reasons
for them viii eventually reveal them
selves. Our government will soon have
established four magnetic observator-
les, besides many temporary places
known as magnetic stations The Ger
mans have recently determined II
establish magnetic observatory in tn.
Samoan islands, and the present ant.
arctic explorations have a direct rela
ton to terrestrial magnetism. 1t is ex.
pected that they will throw some Hgh
upon the magnetic pole at the south
about which less has been known thar
about the one in our hemisphere. Mag
netic observations have been estab
lished all over the globe and they vii
begin on Feb. ], 1902. TO make stimuli
taneous magnetic observations on GER
tain selected days, generally the Is
and 18th of each month. and TO con
tlnue them for at least one year A
these Decentralization forty il
} number-observati of magnetic va
riations Will be recorded continuousll
by photogTa phic appliances.