, 1889-12-26
THAT ECLIPSE.
Observed in Africa Sun
day Morning,
BUT NOT IN SPOKANE.
We Were Out of the Lunar
Shadow.
SCIENTIFIC FACT And FANCY.
American Astronomers Who Went
Abroad to Observe the
Phenomenon.
SCIENTIFIC FACT AND FANCY.

The sun was invisible at 11:13
o'clock Sunday morning, Greenwich mean
time, or 6:13 A. NJ, 75th meridian time.
Total eclipses of the sun take place
about seventy times In each century but
the astronomer who would observe them
must often travel long distances in order
to come within the range of the lunar
shadow. Various governments have
sent out parties to observe the eclipse
itself, the U. s. $. Pensacola having
taken well.equippcd party from the
United States to st. Paul do Loando, on
the west coast of Africa for this pur.
pose, but there are certain other observa-
tions that any observer can make, and
that may prove of interest
At3oclock Sunday morning the eclipse
was observed in other places. Owing
to the earliness Of the hour the darken-
ing ofthe sun will not be visible in this
city.
Just how the solar eclipse takes place
Is shown in the "American Ephomeris"
for 1889, from which it is apparent that
the path OF total eclipse upon the surface
oil the earth must always be quite mar
row. Those tracks always lie in .
often 5000 or 5000 miles in length, while
their breadth is on an average of about
100 miles. A little consideration will
thus show that two total eclipses of the
sun can rarely occur at any given spot
on the earth within q few years of each
York, the last total eclipse took place
toward the end of the eighteenth ccn-
tury, and no other is visible there for a
half century to come.
THE oBsERvERRs STATION.
The first problem of the eclipse OBJ
server is the location of his station. Evi-
IDENTIFY he must be as near as possible to
the middle line of the path of totality,
so that not only may the duration of the
eclipse be as long as possible, but the
moon may lie as near as possible CEN
trally over the sun in order to show the
sun $ corona symmetrically all around
the lunar disk.
Astronomers who have made a spe-
cialty of such calculations have found
that in no case can the sun be totally
hidden by the moon longer than eight
minutes. Less than half this period will
cover the average duration Of the total
phase, and this Is about the condition of
things during this eclipse of the sun,
where the path Of totality strikes the
earth just north of South America,
crosses the Island of Trinidad, and
northerly projection in French Guiana,
| and then skirts across the Atlantic
ocean without touching land until the
province OF Angola, on the west coast of
Africa, is reached. Thither is the party
of American astronomers already pro-
ceeding in the United States steamer
| Pensacola, and under the auspices of
the United States navy department,
which was charged by congress at its
| last session with the expenditure OF the
appropriation for securing observations
OF this eclipse.
| OBJECTS OF SOLAR OBSERVATIONS.
Many people appear to suppose that
the observation of total eclipses of the
sun is connected in some way with the
problem of finding out how far away the
sun Is, but in point of fact observations
of these phenomena have no bearing
whatever upon this question, aud the
most that we seek to do in the direction
OF precise astronomy is to make such
observations and take such photographs
as will enable us to find out with the
highest degree of accuracy the position
of the moons diameter relative 10 that
of the sun at several recorded instants
of observation. AS will appear on a lit
tie reflection this department of the
work of the eclipse observer bears direct
lv upon the betterment of the numerical
data from which the astronomer pre-
diets the position of the moon, and 1t is
thus matter of moment in the future
of the science of navigation, as well as in
the further improvement of astronomi-
cal tables and theories OF the motion of
the moon.
The MORE RECENT DISCOVERIES.
The suns hydrogen prominences are
more completely visible during the prog.
ress of totality than at any other time.
1t is now more than twenty years since
these curious phenomena began to be first
observed without an eclipse, and since it
was found possible to do this, observa-
tions of these reddish protuberances
during total eclipses have largely fallen
into disrepute. But three years ago
Prof. Tacchini discovered that tho prom
inences observed during the eclipse and
subsequently by the usual methods dur
ing the full sunshine were quite differ
ent objects. In fact, the latter appeared
to constitute only part of very intri-
cate structure, while during the eclipse
itself the prominence appeared to be in
part, If not entirely, down rushes OF rel
atively cool material upon the surface of
the sun.
Photography is the most powerful ad-
junct of the eclipse observer of to-day.
delicate test points of observation which
ten or fifteen years ago required the
time and personal attention of the most
expert spectroscopists can to-day be
solved in a much more satisfactory form
by the examination of Photographic
plates properly exposed during the
phase OF total eclipse
AS can we'll be imagined the observa-
tions taken of the eclipse in Africa entail
large expenditures, but modern science
demands that all the details of this
phenomenon be carefully noted and pre-
served