The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1854-05-26

scurauon-tfati is to say the ecpse-w begin es the
Georgetown Observatory at minutes and thirty
ana one nth OF second past four O'Clock in the after
noon-thst Ia, very nearly at two and half minutes
past four The greatest obscuraon Or height Of the
eclipse VIII % at nineteen minutes and three
past hve O'Clock, and the end at twenty minutes
and twenty nine seconds past six Tie whole duration
at Georgetown to the nearest second will two hours
twenty four minutes aad fifty six seconcs
The point on the sohx disc where the cbscuration will
first appear win be at l47I degs from the suns vertex
or his most northery point counting to the right
hence tho general observer will fix his glass sheded by
colored from the strength of tho SUMS rays) to
about tbs southwest further edge of the SUMS face
For the end of the ecse the glass must hs pointed to
2lS degs to the left OF the SUMS verex which will be
on the hther edge, and little east of the SUMS most
northerly point.
The number Of dgits eolrpeed at the Georeotuwn Oh
ssryatory snd sensbly teBame the country round
9sls-that is to say, mere than three-quavters, and
nearly ten .wefhs of the SUMS diameter will be OBJ
scured.
In expressg the magnitude Of the eclipse whether of
she OF the moon it lie customary suppose the
aameters of these bodies divided into twelve eo parts
called dgs and the magntuis of the ecp expressed
by stating the proportion Of the diameter Of the disc
which is obscured Thus when half the disc is obscured
We cay the eclipse measures BIN dgits and so or.
n
paper recently communicated To- the American Assoca-
lion for the Advancement OF Science at Washington
particular attention should be paid to the color Of the
glasses used IN the observation of the eclipse snce the
Phenomena present many different phases, and phases
requiring particular color render observation sat
iffactory.
As 1t had ieen asserted that the moon had heen seen
before the contact of the shadow with the SUMS Disc
suggested that several of various colors
"a Arrn in cu1o frau
central pivot that each glass might its turn
bo brought IA front Of the of the telescope at
the pleasure Of the observer.
The rotary motion might bo rendered steady by
tho pressure of small spring with tooth falling into
ashaow dent in the revolving Frame as ia the case
in the adjustment Of dark glasses use Of in some
sex.ants. 1t would, moreover seem to be advisable
that the succession of tns Of the several glasses
should be such that the eye would not be too much
blinled rendered nsensible by sudden change of
one for another the order being somewhat like the fol-
lowing; white yellow, orange, red, violet blue and if
there be room for them) then green and groensh vel
low to come back, in the circuit, to white again. The
white tint Of sunlight liz preserved when the view is
through Dr.. Maskeynes screen of liquid ink, or the
ike effect may be obtain ID by suitable combination
Of screens of different colors such as for instance vo
let and green gasses the number Of violet glasses being
in excess The singula-ly tinted glass which goes by
best of all for presenting whto image of the sum- as
by it all colors transmitted, although with dmi.
nished intensity
The following directions for the observation of the
eclipse were drawn up Professor Alexander and as
they are for the most part eay understood they can
be followed with PRATT and interest by the m,st un
scientific
Special roughasss 6ssls lines, At the beginning.
First unequiyocal contest,
Distortion OF the cuspS.
Agitation at the edge Of the moon's disc.
Corruscations across the moons disc
An illuminated band bordering the moons disc
EfFEcss soIAs
Polarization OF light at solar spots.
Luminous projections on the moons disc.
Analogous to projection Of the moons disc beyond
that of tha
Color Of the moons disc.
PREVIOUS FORMATION OF RISG-LE LIGHT HE-
TWEEN TUE cusPs
The time of its first appearance.
Its extent in both length, and breadth.
Its color, If invariable;
Changes in the lights iy.tensity or its color
Its apparent motion, any, along the edgo Of the
moons disc.
Its polarization.
Its special changes Just before the formation of tho
It's intensity as Indicated by the depth Of tint Of the
screen. glass traveIsei by 1t.
At FORMATION THE RING, sERRArEp APPEARANCES on
BEADS
The form and changes Of form Of the cusps. The
cusps not unfrequenty have been found to be united
rapidly by ssrrated bright edge, assuming sometimes
| Their motion along the moons edge.
Time Of their and their exact duration
Their color and its changes.
Time Of complete formation Of the ring.
The 5rk lines, which have been so often noticed at
the second and third contacts and which, in conse-
quence of having been minutely described by the late
Mr. bailly known by his name; some particulars to
be noted with regard to them specified in the case of
Whether the ring, when completely formed, Is found
to be any broader or any narrower than the beads.
WHILE THE RING EsDuREs.
The projected shadow Of ball, and It's colors II any,
The extent and variety of the coors Of the solar spec
trum, and their dark lines
The special changes of outline Of the moon BY en-
croachment of light or by distortion of the disc.
| The coior Of the moons disc.
| Tie angular breadth Of the ring
Tl,e moons diameter.
AT TIE RUPTURE OF THE RING.
The same phenomena a at the formation though In
| MMEprATELy AFTER THE RurTuRE OF THE RING.
As at the corresponding period before the formation
| but also in the inverse order.
| BrrwES THE RuP1URE OF THE RING AND THE END OF TIE
| EciIfsE.
| As in the analogous period after the beginning
| AT THE END or THE KcIIPsE.
Time OF the last unequivocal contact.
CONTINUED AnuEsIoNs, ETC
As at the analogous period preceding the first decided
/ AFTER END THE EcIPsE
Same appearance TO be sought for as before the be
ancrIasEous OBSERVATIONS AT VARIOUS TINES
| Temperature in sun and shade.
Photometric observations.
Change Of dew. point and deposition Of dew.
| Polarization Of the light Of the atmosphere.
| Polarization II Its heat.
| Tint Of the sky.
| Course and variable force OF the wind.
Change, any, Of magnetic intensity.
EcLrPsEs VIEWED HISTORICALLY.
The rst solar eclipse Of which have any authentic
record occurred 5s5 years before Christ and was pre-
dicted by Thales singuarly enough and as II In ac
cordance with and corroboratng the popular idea con
cernng ecpe that they only appear in time Of trouble
we find them generally speaking, either preceding OF
contemporsneous with wars, pestilenee, or famine.
In $50, D. G., Nebuchadnerzar was King Of Babylon
and his reign was continued series Of aggressive
In 424 b. c. eclipse was observed at Athens, and in
the following year there terrific earthquake which