The times. [volume] (Washington [D.C.]) 1897-1901, 1900-05-28
PATH OF THE SHADOW THROUGH UNITED STATES

and shade. They are easily visible against
white background, such as a sheet fas-
tened upon the ground. By means of rod
across the sheet the direction of the pove
ments Of the shadows may be observed, the
direction being different before and after
totality. These bands are observed one
minute before totality and last one min
| ute after. 1t is desirable that observers
count the number of bands per minute.
Amateur observers may be encouraged in
| learning that some of the most valuable
! observations of past eclipses have been
made by amateurs with small cameras.
| For observation of first and last contact
| shade glasses are necessary, the best being
! long wedge of colored glass tightly ce-
mented to similar wedge of white glass.
Red. which is commonly used. is said to be
poor color and some neutral color. dark
green or dark blue. is recommended by
many. Owing to the shortness of duration
of the total eclipse astronomers advise
tina: every observer direct his entire at
tention to some particular feature of the
phenomenon and sketch or photograph
with a special view to completing that one
feature. as otherwise his model will have
withdrawn before he is satisfactorily ad-
vanced with his work. Cooperative
groups of sketchers. with their work care
fully planned and divided have hitherto
done good work Many astronomers have
been hard at work with models prdcticing
for speed and accuracy.
Problems in Astr0nom,.
One of the astronomical questions which
it is hoped may be solved today is that Of
the existence of an intra- -Mercurial planet.
AS Mercury is at this time very close to
the sun, 1t is probable that that planet,
the weather being favorable, will be visi-
BILE in Washington and other places
within the partial shadow and sufficiently
near to the path OF totalty. and it is pos
sible that the star Alpha Tauri will like
wise be discernible in these localities
Within the path of totality stars as faint
as the third magnitude will be seen. and
the telescopes and cameras of the astron-
cmers will disclose far more.
1t may be that photography will settle
the question once and for all. of the ex-
istence of an intra Mercurial planet AL
though the orbit for this planet has been
computed and all its movements accurate
ly determined by Leverrier. the French as
trcnomer its existence is by no means GER
tain. 1t is, III fact, only an hypothesis,
constructed to account for mysterious per-
turbations in the motions of Mercury. The
Harvard College corps of observers sta
toned at Greenvilie. Ala under the charge
OF W. H. Pickering, have devoted them
selves especially to the determination Of
the presence of this suspected plan
ct, depending for that purpose entirely
upon their Photographic apparatus. All
astronomers will be on the alert for
comets as vast numbers OF these solar
derelicts are probably circling about the
sun.
AS may be judged from the preparations
made by astronomers. the greatest inter
est, scientific as well as popular, centres
in the corona, the former because
It is now the only solar feature which |
can be observed only at the time Of
an eclipse on account of its sp!eudor. The |
structure of the corona offers the most |
magnificent field for scientific investiga-
ton which it is possible to imagine, as |
upon this may depend the solution of the |
question as to whether the sun is, in real |
ity, flaming mass or the generator OF |
some active force, more or less similar TO |
electricity, OF which light and heat and |
magnetism are merely results
1t is described by astronomers as
a kind of envelope surrounding the sun. |
and extending for millions of miles away |
from it. Part of 1t is made up OF the in |
visible gas, coronium so-called, which |
surrounds the sun. The pres