The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1874-12-19

- - e+ee@t1 WIZ can recall
their first lessons in astronomy win renon.-
Der the familiar statement that ..the sun i
ninety-fve millions Of miles (in round
numbers) from the earth. This vas t6e
orthodox astronomical belief for 1 hundred
years before the last eTrauait Of Venus
(l769,) and remained 50 for nearly
hundred years after that event some
closer calculations Of Tie observations AZ
that transit, which we're eompleted by sbe
astronomer Encke, about The year 1924
made the distance from the centre of tbe
sun s5,s70,ooO miles So The old formula
o. ninety-hve millions Of miles remained
sufficiently accurate for popuIar use. md
90 retained iis place in the school assra,.n
mics But i was mot yei precise enough
Tor the use Of the nautical almanac makers
those practical astronomers and me,be
matical computers, who have to calculst.
.he movements and positions Of the
heavenly bodies for several year. !,
advance, for the use Of navieators Of ~
nigh seas. These latter, in making tbe;y
poriloas voyages through the pasbles
waste Of waters have no sure guides but
their chfonometors aud the movemen,s
ana positions Of the sun, moon and st.rs
y n, therefore, in the highest degree
essential to their safety shet tbe chance.
for error in the nautical almanaes sbslI bo
reduced to the lowest possible minimum
y y Tor tins reason that there Is 50 m,eb
solicitnde concerning the precise dis.apee
Of the earth from the sun aud The ,,oon
and the other heavenly bodies w;th;n an
planetary system; it is for this reason tbst
such minute, careful aud exhau.,;ye ob.
ssrsetions are made; ID is for this reason
.nat not only years, but centuries ars
devoted TO continuous observations Ind
hnally it is for this reason that there i 8
much discussion just now Of The present
"iransit Of Venus across The fsea e ~
sun, which was being observed last p,gb,
Dy scores of American and other astroso.
mers, stationed 10 the Eastern bem;s,,be,s
for these "transitsn furnish one Of tbe bess
means Tor measuring the SUMS distape.
from the earth. M
About twenty years ago, however, the
desirability Of greater accuracy Il ri.
measurement started number az otbsr
methods for testing, revising and correct
ing the accepted standard Of distance
Among these are exhaustive calculations
Of the effects Of the suns attraction on ,be
moon; and Of the relative weight Or tbe
sun and earth, and the consequent distance
which ought TO separate them in order that
the centrifugal motion Of the earth Il Il
orbit shall precisely balance the attraction
OF the sun. And there have been ain
other verifcations attempted, based upon
observations Of the planet Mars. and az
the time required (49s seconds) for LIGHT
70 pass from the sun to the earth
The result of al these laborious obserya.
tions and computations was to show tbst
the s5,s7o,ooo miles Of Encks were To-
great, and that the real distance i some.
where betwecn s2,2Oo,oOo and s2.7oo,-
goo miles Here, Notwithstanding an me
care Of the observers and ali the nice and
delicate methods Of modern scieuce and
mechanical ingenuity, there is still an
uncertainty, to the extent Of half million
Of miles-great in absolute fgures but
not much in such vast distances. vet st;lI
enough to make it highly desirable 70 ret
closer, and this is what our American
astronomers and photographers, with their
foreign colleagues, were trying to do watch ]
ing the Transit Of Venus" last nieb. an
the opposite side Of the globe, where m i
was broad daylight.
Some Of these American astronomers
and photographers are stationed en- desc.
late islands in the vast Southern Ocean
some in New Zealand, some ii Australia
some in Japan and China, and some ii
Northeastern Asia. This wide distr;bn.
tion Of the observing parties Is made parsly
for prudential reasons, in order 10 increase
the rha r,rs ,.sr E..,.... = 1.lsl5