Omaha daily bee., 1916-11-30
Personal Gossip Society Notes Womos Work Household Topics

CD, which is parallel to Alb and tan
gent to the pcnumbra and earth, are
all so close together that they prac-
tically coincide.
The second exceptional popularity
of the present eclipse is the fact of
the rounmbra's falling beyond the
south pole, where on the diagram
north and south exchange ma mes, and
east and west rs well. For this rea-
sun the pcnumbra moves aga INST the
diurEal motion OF the earth anC there
fore shortens the duration OF the
eclipse, whereas If II were placed
higher up on the diagram it would
move with the earth, as II generally
does, and lengthen the time Of the
eclipse,
Thirdly. the line CD, the northern
limit of the eclipse" enters upon the
earth at point to the left of the
line Ms, so that CD crosses Ms on the
earth's disk, AS the local time on this
part OF the line Ms Is midnight there
is, in fact, an eclipse OF the midnight
sun, That the line CD does really
enter the terrestrial sphere at the
place mentioned, as well az all th2
eother data that are necessary for the
construction of the eclipse map, could
hNNVa p' Nh'"h w NNNh
scopic examination OF figure |. Re-
course had to be had to rigorous and
lengthy calculations, which alone
could ferret out the desired knowl
edge. Deriving the necessary data
from diagram like figure is al
ways very easy and expeditions
method, when the penumbra crosses
the earth somewhat centrally Here,
however, the graphic method fails ut
terly--another popularity of the pres!
ent eclipse which specialists will APP
preciate.
Fourthly and lastly. perhaps the
most exceptional popularity of the
present eclipse is the fact ot Its oc-
curing for most places within the
eclipse region-on Christmas eve, for
some at Christmas midnight, and for
some others on Christmas morn.
Let us now look at figure 2, the
eclipse map, and see what wonderful
facts calculation has elected from that
minute portion Of figure |, where the
moons penumbra passes across the
earth's disk.
The first thing we notice on the
map. figure 2, Is that south is on top
and west to the right. in other words,
that the map has been apparently re-
versed. This was done on purpose in
order to facilitate comparisons of fig-
ures l and 2, The numbers so, 40,
80, 20, 10 below mean the degrees OF
east longitude, and rs. 10, 65 to the
right the degrees Of south latitude,
The broken parallel Of latitude is the
antarctic circle, ~.
The point C is where the line CD
Of figure l enters the earth and the
point ID where 1t leaves II. The half
ellipse marked northern limit lof
eclipse Is the projection of the
straight line CD of figure I on the
spherical earth, distorted partly by Its
rotation. The point &c on figure 2
Is the place Of first contact" the
very first place .on earth to see The
eclipse begin, and LC that OF last
contact" the very last to see It end,
The point GE Is the place OF the
greatest eclipse" where per cent Of
the suns diameter Is covered by the
moon. The dotted curves tangent to
the northern limit at the numbers
30, 40 and so on are successive pro-
jections of the circular rim OF the
moons penumbra at the correspond
ing minutes after p, m, central time,
The last one to the right. however, Is
the one for 2s59. The eclipse begins
at those minutes all along the western
portion of the curve from the num-
Der on the northern limit" line to
the curve ECLIPSE begins at sunset"
and ends along the eastern portion
from this same number to the curve
ECLIPSE ends al sunset" The penum-
bra moves westward, as was said be-
fore, instead Of eastward, as in all
other eclipses.
The shaded portion near the letter
M shows the region where the Christ
mas midnight sun will be eclipsed To