New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1869-08-06

two eepses OF the sun every year. and that there
sometimes four, five, while sometimes whole
passes by without any eclipse at all Of the moon
and on the there but 20 ecses OF the moon
to Al OF the On the ether hand the universal expe
rence is that eclipse OF of too frequent oc
10 attract much attention, and almost
has least total eclipse of the while
eclipse Of the however small matter Of curiosity
and as large an eclipse as win visible tomorrow
occurs but two three times in generation. No as
tronomer known TO leave his home TO witness
an eclipse OF the moon, but scientific expeditions
sent the world TO witness total eclipse Of the sun
The cause OF this apparent Inconsistency is this when
the moon is collapsed, by passing through the earths
shadow the eclipse may be seen wherever the it
self is visible which will be to the whole Of that side Of
the earth which 1t happens 70 be- But an eclipse OF
visible only to that small part Of the earth COW
cred by the shadow; and it is frequently the case
that the only portion Of the earth whcha eclipse is
visible is the neighborhoOd Of the North Pole where OBJ
servauon would be difficult in the stll more lmprae
toable region OF the Southern Ocean.
But the size Of the shadow OF the moon, within which
the sun appears totally ecpsed by means the size
OF the moon itself II observe the shadow Of marble
upon sheet of paper shall find that when is held
near the paper shadow will be nearly large the
marble itself; bat drawing 1t back. it will become
smaller and at distance OF about five feet it will dsap
pear So, II hold up the marble between the eye and
the sum- will be observed that the is entirely hidden
or ecipsed by it; but the marble is withdrawn TO
distance Of five feet from the eye It will be apparently
of the same size the sum- exactly covering its disk
and drawing it back still further looking with a
smoked glass; unless the atmosphere hazy it will be
seen that the cannot any longer be entirely
hidden by marble At the distance at which they APP
pear Of the size the shadow is mere point Now
the appears almost precisely Of the size OF the sun
and the consequence is that its shadow, when the
moon is nearest us, instead Of being 262 miles in diam
eter can than IFS miles in diameter; and
frequently the that the moon SO distant that
its shadow does reach the earth at ALL In that case
as occurred in and will again In 1875 there IS an an
nuar eclipse Of sum- which the shines around
the moon, q ring instead Of being completely covered
by it,
In the eclipse tomorrow, the diameter Of the moons
shadow IS 40 miles. and the only be totally
ecpsed at time TO those persons who may be
within that little circle of 40 miles in diameter where
the shadow happens 70 fall at that time The motion
of the and the motion Of the earth its axis
combine carry that shadow along the surface Of
the earth in a narrow, rbbonlike line, which may be
marked out beforehand with exactness In the accOmpa
nyng map this ne within which the total eclipse is Wis
ibe may be commencing Alaska, and passing In
a southeasterly direction through British America
Montana, Dakota, Nebraska Iowa, Missouri, illinois, |
Indiana, Kentucky, Tennessee, and North Carolina To
person observing from the central line inter |
mediate between the boundaries Of this ribbon, the |
will be totally eelipsed from min % sec to min
sec, according 20 his geographical position that being
the time which it will take the moons shadow to
ts own diameter But observers not upon the central
line over whom side Of the shadow passes will see
1t eclipsed for Ghorter time. To observers upon the
outer line the total disappearance Of the win be only
few seconds. The chief interest in solar eclipse
IN the observations which may be made within this rib
bon of ternOry and hence astronomical observers are
locating themselves nearly possible upon the
tral line But comparatively few of readers will
be favored with that most imposing spectacle we will
first proceed to consider what be seen outside Of those
limits.
Resuming our marble experiment, again placing it at
distance Of five feet from the eye, and bringing it be-
tween the eye the sum- will be that IL IL does
not pass centrally the and entirely hide IT,
may still hide portion Of IT, that portion being greater
the nearly the is to the exact line OF the shadow
Of the marble Astronomers indicate the proportion OF
the disk Of the sun which is ecpsed at any particular
place by dlgts dividing the diameter Of the sun into
twelve digits We have shown upon map only |
the ribbon Of territory within which the will be to-
tally dgts eepsed but also the lines at which
will approximately ten dRits, eight dlgts, and six
dgts ecpsed. Thus it will he seen that in the City OF
New-York there will be somewhat than ten digits
eehpsed.
EVERY MAN HIS OWN ASTRONOMER
The appearance Of the during the eclipse may be
very readily shown in the following manner: Lay |
penny upon piece Of white paper, and draw pencil
line round IT, This circle will represent the sun sui
GENTLY WELL although it will be little larger than the
penny ITSELF which 20 represent the apparent size OF
the MOON whereas should be little smaller Drawing
line around hyecent piece for the and then using
RtwO-cent piece for the moon, will be more accurate.
Now divide the diameter of the circle into twelve equal
parts and draw line three inches long through
the division corresponding to the number Of digits
eclipsed. Thus. for Boston or any other place
about half way between the lines marked on
the map 40 dgits7 and "s digts" respectively, the
line will be drawn through the ninth division, count
Ing from the bottom. On the south side OF the line OF
totalty, as at New-Orleans, the divisions would be
counted from the top Next We must devise means 20
hold the paper that this straight line shall be parallel
to the moons orbit East Of the Mississippi the eclipse
occurs late in the afternoon that this may be done
with sufficient accuracy for the present purpose in the
following manner Make dot one inch above the line
already drawn and toward the right From that dot
draw toward the left line two inches long, that It's
eft end shall just touch the line previously drawn This
new line must be held horizontally IN order TO show the
phases Of the eclipse in their proper position We arc
now ready TO see the eclipse. Lay the penny the
paper, with its top Just touching the first line
% the right Of the circle, and the penny carefully
along the line until it begins TO hide the circle We shall
hen see the will first appear upon the SUMS
surface. Continue TO the penny slowly and care
July along the line and will successfully represent all
he different phases Of the eclipse from that
place II the position OF the observer is TO the south OF
The line Of toaty he will proceed in the same way OK
,eptng that the bottom Of the penny must be moved
along the line BY the aid Of map and these instruc
hons our readers be their own astronomers to-
morrow provided they know the times Of the beginning
and end Of the eclipse These times can be nearly Cd
tanned from the following table, for the places mentioned
in r. and for other places by estimation from the nearest
Mace contained In the table, observing that the further
west the place Of observation the sooner will the eclipse
commence: .
Eud