Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1873-08-28
IEiscetIany.
GREEN WTCH TIME.

NEVER had science more pIeasant re-
treat than Greenwich Observatory aDp,ors
To be, This bright summer morning.
for all lis pleasant aspect, however,
the idea of exploring il is decidedly n
formidable one. At the very entrance
gates, one feels suddenly convicted of the
most ahlect ignorance Here are mystnr-
ious metal pins fixed on the wall for the
determination of British measurements
and the question at once arises. What have
these to do with astronomy? Then there
rs a great clock-dial on which the hours
are reckoned from one to twenty-four and
which IS popularity believed to bc kent
going by the sun
determined 70 clear the way as he Coes
on, the visitor makes these outer dificul-
slee the subjects of his first inouiries ON
gaming admittance, and he discovers 10
ms amazement that the very length ofbis
trousers, and the cut of his coat and fbr
height OF his hat have all been determine
eu ny measurements based upon the mo-
liofs OF the heavenly bodies.
\ tallor's yard measure, it appcars
bears certain proportion TO the lenrth Of
a pendulum which, under specified condi-
lons, beats accurate seconds of time and
seconds OF time are determined by astro.
nomlcal observation. If the tailor wishes
go verify his measure he has only to bring
i % me observatory gate, where he will
Find a standard absolutely accurotr A.
20 the clock, 1t is an astronomers clock
and astronomers know NOTHING of a m :
ana p. ms; their calculations are sufIfc.
ientiy complicated without them. The
notion that 1t is kept going bv the sun is.
II Ieed hardly be said, a mere delusion.
On passing the outer portal of the oh
Seryatory the visitor finds himself in an
open courtyard, with an irregular pile of
9ullulngS on his left hand. Entering \
low doorway IN one of these, he is at once
interested TO discover that he is really at
what may be considered the fountain
mead OF all our computations of time. The
thlet business Of Greenwich. as all the
world knows is to tell us the time of dav
and IN this small and somewhat mean,
looking apartment is the great telescope
ny which observations for this purnose
are effected.
Inns InStrument-the transit circle as it
Is technically called-is twelve feet in
length and its largest glass is eight inches
tn diameter. Ii is suspended by the mid
u'e between two massive stone buttresses
~ such manner as to permit of its
weeping Ihe SKY IN straight line over
noau! though 1t cannot be veercd round to
the right or left
we have arrived, let us sunnoSe LITTLE
before noon; the sun is about 10 cross tbc
meridian, and an observation is 70 he
made. Shutters in the roof are thrown
open, the great telescope is swung up ana
lAed IN position, and an observer seats
himself at the lower end Of it. While we
are waiting for the great Iuminarv, let us
."Ne peep through the instrument All
49, can oe seen IS a number of vertical
ny. e.S-'echnically called wires, though
tiiC3 az IN reality 50 many pieces of cob
s'Letehea across the field Of obser-
Natloh - irregular distances. The center
one Is the celebrated meridian of Green
Wien or at all events ii represents II and
II lS curious to reflect that from this CON
Ter line ships Of all civilized nations end
IN all parts OF the known world arc roniy
onlng their distances; that this IittIo nieeo
Of cobweb IS, practically, all that divides
the world into eastern and western bemi-
spheres.
While we are peeriEg along the tele.
scope, the drowsy ti2kling of innumerable
clocks Is heard through the still summer
alF, and we begin to think that for once at
least the sun is behind time. II not, then
seems plain that all the Greenwich
CLOCKS are wrong, a supposition which is
quite at variance with all our traditional
ldeaS OF the place. On inquiry. ii is graft
lSlng to find that our faith in Greenwich
!lmepieces IS perfectly justified, and that
really IS the sun that is behind time.
ne apparent motion of the sun, as every
body knows, is really the motion of the
earth. Now the earth moves round the
sun IN kind of oval pathway When
sle IS on either side of this oval her