The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1874-05-11

70 put up their ODbofvlnk nuts, mouut tueH 1nStfu-
ments and do their work well when tney get TO
Washington. and PROBABLY OF an the other great
onseryatSries abroad. have been Tor some nne
- LITTLE DISSENTING nUrR m saey
AND as oue are
within the grounds. and the chiefs and their assist
ant astronomers and PHOTOGRAPHERS are a. hive
OF bees busy In their practice. IL may be Thought
easy enough Tor an observer WITH good telescope
to detect the instans OF true interior contact OF
Is ssS not Tie Case .' oSns 70 perpiexlns optical
phenomenon termed irradiariOn the BRIGHT sun
:: 1s ss a1S s ss
have competed her ingress OF gotten fairly lnslQe
OF the SUMS outer limb, she has somewhat pear
edge by dark band which shrinks into u line and
at last breaks. This is known 70 astrono-
the e'' transit with any hope Of success in
It's great results, therefore,, close practice here
ssdts g. sSs enSae srens %
stances and TO different observers. models Of the
transit have been In working order, as at WASH
opening 10 black metal shield towards station
some hundreds OF feet distant Across this OPEN
to travel with velocity corresposdns with that
which Venus win have From the observing sta
zion the astronomer must deal long and carefully
with this phenomenon before he leaves home.
!. When our chiefs and their photographers, go
they VIII take also for each party one nve-lnch
Avian Clark, OF Cambridgeport; one transit in.
strument thirty inches local length and OF two and
Sa Sew ydrs ae
scope OF the new plan, prepared by winiock, OF
Harvard. with the necessary Photographic DALI
q lnll supply OF chrOn ometers and OF the meteor
illogical apparatus needed. &c.,
the RELIANCE OF THE AMERICAN PARTY
being very largely on photographing the planet an
the way along her passage across Apoli0s Face,
great care IN practising photography s being ex.
one known to be skilled IN hts profession; anu
to perfect further their appliances and work, Dr:
Chapman, also Of our city, are counseling our
observers and practising the younger artists.
WHAT IS ALL THIS FORT
inquiry; still less to crafty the astronomers
curiosity or to exalt hts reputation. The great
object OF the transit to determine more accurate
the sun from our little planet. The issue OF the
know the distance within $4,000 miles or the
om this ws fs the 1ss SPACE ss BEEN
ooOo00 OF miles; and II any one asks further Of
what real use 10 this to the world we answer that
ments OF the heavenly bodies tand consequently OF
helping to determine for the mariner his longitude
veyor or the yardstick to the merchant. Until
we know the sun's distance we cannot know his
bulk OF weight or the truth about the sun Spots.
atect our CYCLONES on land and sea. We must
learn 1t more carefully In order perfect the lunar
for the geographical position OF places on land as
well as At sea- 1t IS curious to find at different pc
RODS in history .
HOW FAR OFF THE SUN HAS BEEN SUPPOSED TO BIZ.
The different estimates OF tina are strange land
marks Ia the slow progress for q long time made
by man toward true knowledge OF the heavenly
bodies. Herodotus says that the first dawn OF
thought as regards the SUMS distance made its APP
these thoughts from the opinions OF the earth
and OF the universe then generally held BY the
learned Greeks. These were that the earth was
dat plane, whose centre was at De PHI; tnat the
sun was merev secondary. uncertain ana easily
Influenced body, which moved about Qr over the
earth, but was itself acted on by the same forces
which we see acting around us, but 70 80 great an
the Etesan winds Herodotus thought this most
PROBABLE. From this we may fairly Judge that the
ala po ne Sres ann s be-
than ten miles from the earth, for they did not
consider the winds at any greater distance.
affirmed the rea! size OF the sun TO be as large as
the Pe.oponnesus; such q size, considered In
indicate . distance OF 1900 miles. "A century
later, about B. o. ESQ., Artstarchus. the astronomer,
saos ,r ~ tne o. Vas e
least $500 00O miles on. HIS plan was ingenious,
but ms ss 1 srs
Hlpparchus. computed the SUMS paraIlax TO be
three minutes-twenty times 1t true vaine. Then.
further down Times stream, the famous old KepleI
MADE the SUMS distance to be 26, 100000 miles.
our late school ASTRONOMY distance Of o5 ooo, GOO
and this py rediscusstOn Of the observations Ol
a7ss oy E9cke stone g, eoo and NswcoW5 has been
the parallactic angle, the 'parallax OF the sum-
or the apparent change OF q heavenly body IN ita
FOR Instance. the Northern and southern neml-
spheres, as IN our present experimentation
Mn angie Or ne It's Sa tine
duced. It will be reduced yet more.
THE TRANSIT OF 1869,
the only one before this ever fairly observed, IS
memorable largely for its connection with the IA
nous voyage Of discovery OF Captain James Cook.
distant places. The English fitted out Cooks ex-
ploling expedition, win instructions to observe
this transit on the island OF Otaheite. Cook, an
assistant from the Royal Observatory, and Dr. SO.
lander. made observations at point IN Tahiti
known to this day as Venus Point. Many other
Wales, Hudson Bay; san Jose, California; Kola, IN
Lapland; In all at hity stations IN Europe SIX IN
Asia, seventeen IN America and one 10 Polynesia.
From the Investigations OF all the observations,
Encke, in 1874, gave tue value Of the solar paralax
as S.6776 Notwithstanding to making the sun g
copied until the present day; recently reduced to
between 1000 600 and 81, O00, 600 miles.
ps sSe q coos sfe
still greater direct service to the geoerapher. I'm
l17o after observing the transit, ne discovered
New Zealand to be an island. He clearly proved
on his second voyage tue non-existence OF the
South Continent, which, tin then, mad been
pfodigaly displayed,n as DR.. Neumayer says on
the maps, reaching as far as twenty degrees south
into the Pacific; and on hts return, as is well
known, he discovered the Sandwich group. And
il is matter oil interest that all his explorations
in the southern hemisphere, beginning with those
connected with his visit to Otaheite for the tram
sit, should now, after the lapse OF one century, be
re-examined by those who have been busy ever
since 1870 In considering those same distant
regions for new expeditions Tor the same great
obect-the transit OF Venus and las announced IN
the letter OF che American Commission to the
Secretary OF the Navy 1.-THE determination q the
accurate position Of numerous points IN tue Pacific
Ocean," This Is another important result to be
aimed a. that BY the assistance OF Captain Chan
dler, commanding the Swatara, anu mis- naval
officers may be attained. It Is like toe other gov
erbment surveying objects now gong on In the
Pacitic--our ocean. W
HOW Is THE SUMS TRUE DISTANCE TO BE DIsCovEREDs
The answer to this, which we quote rom Pro-
lessor Hilgard, appears the most satisfactory. IL
shows the case without u diagram, and explains
why 20 many observers must go north and south.
AT q point IN Australia Venus Will be seen as y
small black spot on the lace oil the sun, about one
tenth OF It's diameter from the northern edge mid
way on the corresponding chord. This Is what
Is called the conjunction OF the planet. Now, to