The times. [volume] (Richmond, Va.) 1890-1903, 1897-05-14

The Elements Thereof Have just bee" ~
termined AT This city.

on account OF the vast interest BON On
sea and land. involved in coiif 49, 49,.
EDGE az the laws which govern inc nee
ratfc ra.dla Congress has authoil1,u ''io
United states Coast ana Gecoeuc S"i
~ investteate tho magnetism OF tne e"i'.'
in every section Of TIE Not'h N''l l,,-.,.'
continent and to prepare Mashe"' ~'''''
for the whole region - o,o-
In connection with this work '"' ~
monts Of the earths magnetism l'"9 '
been determined at Richmond ' a.
1t may be OF interest TO know ln"s -. -
has been established, and marheo W..
substantial granite posts, az tiie ~
Reservoir Park a true asttohoiiic"i ~
ridian. where engineers ana SUI
can now determine the variation (dechla,
tom of the needle for themselves, as Wen
as the index error Of each mdiyidual IN
strument
The CITY Engineer Is familiar win me
location OF this meridioual line. Al the
present time. az the New Reservoir PARK
as determined with am improved MasHe-
tCmeter and o. COlimatcr Magnet Hi'i"N
Of q hardened steel cyciindcr ana sus-
pended by a delicate silkon hher I'M
mersed in elyCorine The magnetic neeoie
noints minutes 80 $40 seconds west OF
the true north, che direction OF the po'e
of the car.m. This Is the average Vafia-
ton for the twentv-four hours.
At this season of the year the daily va
ration amounts 90 about minutes OF arc.
The north end Of the needle points about
minutes nearer the true meridian 81
A. NJ. than at y. NJ.
The annual variation seems 20 be IN
croasing at Richmond at the rate OF ABOUT
@ minutes of arc each year
The line Of no variation, or the Inc
along which the needle points true north.
passed through Richmond about $50. IL
has been moving westward ever since.
The north end Of the needle has hcen
moving toward the west. at Richmond.
Va. since 1872 You may say. since we
have bad very trustworthy observations.
IL may Doe interesting 10 note the possible
effects upon boundaries Of contiguous
properties. on account Of these remark
able changes I'm the conditions of the
earths magnetism.
Should q boundary line a mile IN
length. which was run I'm the vicinity or
Richmond. Va. say in 1925. with n sur
vevor's compass Doe rctracod az the pres
ont time. and these changes not noted.
there would be an error I'm the location
of a corner Of an least 225 feet.
Should this same line be run Cat this
season of the year, with a surveyor s.
compass at Z A. NJ and az p. NJ, an err
ror I'm the location Of corner OF az least
70 feet Is possible Engineers by the use
of this standard meridian can correct
many Of these errors.
The magnetic dip and the intensity Of
the earth's magnetism, have also been de-
terminod at Richmond, Va.
These determinations are essential 70 a
systematic and exhaustive discussion or
the magnetism Of the earth Is a whole
In the immediate future. similar deter
limitations 10 those at Richmond viii be
made al the following county towns in
this State and an astronomical meridian
marked with substantial granite posts Will
be established AT each place: viz: Acco-
mac Norfolk. Greenville. Halifax. Abe
marie Shenandoah. ROckbrdge, Mont
gomerv and Washington.
The State Of Maryland in connection
with her Geological Survey is establish
ing and marking similar meridlonal lines
at every county seat I'm the State.
]. p. BAYLOR.