Evening star. [volume] (Washington, D.C.) 1854-1972, 1900-05-23
THE SOLAR ECLIPSE
Pamphlet Giving the Plan for Making
Observations.
DESCRIPTION OF TEE SHADOW BANDS
Government Parties Stationed Along
the Belt Of Totally.
THE LOST STAR VULCAN

The Smiths onian Institution has issued a
pamphlet prepared by Prof. S. P. Langley,
director of the aStrophySical observatory.
stating a plan of observation of the total
eclipse of the sun Monday next by which
amateur astronomers may be of valuable
assistance to science in general and add to
the information on the subject of solar
ecliDses
One of the most peculiar appearances. 1t is
stated. attending a total eclipse of the sun
is that generally known as the shadow
bands They are long, dark bands, sep
arated by white spaces, which are seen on
the ground or sides of buildings just before
and just after the total phase of an eclipse,
moving rapidly. 1t is probable that they
are not real bands. but are composed Of
dark patches which seem to the eye to
make long bands. Their cause is not yet
clearly known, as the observations in
former eclipses are quite discordant.
Information is desired upon the following
points: "a The direction in which the bands
90 the velocity with which they move; "a
the width of the bands, and 90 their dis
lance apart. All of these are likely to be
different before and after the total phase.
so that two sets of observations are needed.
The following suggestions. compiled from
many sources, are set forth in Prof. Lang
ley's circular:
Spread white cloth or piece of canvas
upon the ground in any convenient open
space. 1t is well to spread two pieces of
cloth. one to be used before the other after
the total phase. Let each observer be fur
nlshed with four straight sticks Common
laths will do. numbered l. .. ) and 4.
About three minutes before the time Of
totality let the observer stand near the
cloth, with his back to the sun. and watch
the cloth intently. If bands or dark patches
a 1ny f,,a tialy do, to- r..
ton in which they lie: after this is done
place a second stick (2) in the direction in
which they are moving. Both of these OPP
erations should be done deliberately, not
hurriedly, and the sticks left in position.
During Totally.
During the total phase the observer is
free to enjoy the scene or make other OBJ
servations, but it may be we'll to note il
any bands can be seen during totally, as
some have asserted.
At the close of totality the observer
should be at the second cloth, or at an
other part of the single cloth Gf he uses
tons made before totality, placing one
stick CD down in the direction in which
the bands lie and another "a in the direc-
ton in which they move.
If two persons make the records one
should confine his attention to the direction
in which the bands lie, the other to the di-
rection In which they move
1t has been suggested that the whole phe-
nomenon of shadow bands may be unreal
and due to overstrained eyes. Prof Lang
ley points out that it is therefore best for
this and other purposes to screen the eye
by a lightly smoked glass until just before
darkness comes on.
AS the phase of the eclipse in Washing
ton will be so nearly total it is possible the
phenomenon Of shadow bands may be wit
messed here: In regard to photographing
the bands Prof. Langley says:
1t will be most desirab BILE, but difficult to
add to them any Photographic ones. The
difficulty arises chiefly % from the fact
that the bands are moving with consider
able rapidity and can only have their
images taken with a rapid exposure, and
CD that they are only to be seen when the
suns light is nearly extinguished or when
the suns rays are just reappearing, so
that there is insufficient light for the
very brief exposure in question. This need
not, however, prevent the attempt being
made with even an ordinary kodak. Such
photograph will not give the rates at
which the bands are moving, but it will, II
successful, give their inclination and gen
eral appearance. white sheet should be
arranged in convenient manner to receive
the shadows and the camera placed in DO
sition and focused on the sheet. OF course
qu1ck-actlng plates are to be used, and by
preference an exposure of from one-fiftieth
to one-hundredth of second with the full
aperture of the lens. The films or plates
should be signed the film or plate and
sent with any written observations, in a
pasteboard box, such as the plates are
usually packed in. and this nclosed in
wooden box, to be mailed under a frank
furnished on application, addressed to 8.
P: Langley, Smithsonian Institution.
The circulars, containing much more de-
tailed information and a blank form of re-
port may be secured by addressing the
Smithsonian Institution.
The Plans Complete.
All of the government institutions b.ya
completed their plans for the observance
of the eclipse of Monday, the 2Sth instant.
Three parties from the Naval Observatory
one from the Smithsonian Institution and
one from the United States weather bureau
are already stationed at different points
along the belt of totality, which stretches
from New Orleans, La, enthusiastically
across the country to Norfolk, Va, where
1t passes out into the ocean. The Smith
at Wadesboro, N. c., and will include
Prof. Langley, Prof. G. E. Hale of the
ierkes Observatory and a dozen other OBJ
servers. Prof. Langley will superintend
which it is expected to secure a view of the
suns disc fifteen inches in diameter and to
possibly gain an impression of the lost
star Vulcan.
The plans for the three parties of the
Naval Observatory We're made by Prof. S.
j. Brown of that institution. The parties
are stationed at Pinehurst. N. c.; Barnes
Vile. Ga, and Griffin. Ga. At Pinehurst
will be Prof. A. N. Skinner of the observa-
tory, whose staff consists of Messrs. Eich-
elberger, Lawton and Cotton also of the
Naval Observatory, and Messrs. Ames,
Dorsey, Huff, Gilbur, Parsons and Wood of
Johns Hopkins University and Prof. Chase
of Yale. The Barnesville party will be in
charge of Prof. NJ. Updegraff Of the Naval
Observatory. assisted by Messrs. See, Hill,
Littell and Peters, also of the government
observatory; Prof. Lord of the Ohio State
University and Prof. Posh Of Bayport, R.
I. Prof. U. J. Humphreys of the Unver-
sity of Virginia will have charge of the
party in Griffin, and will be assisted by
Prof Mitchell of Columbia University, New
York: Jewell of Johns Hopkins. Crew. Tat
nall and Dinwiddie of the Northwestern
University.
Prof Cleveland Able and Mr.. Frank H.
Bigelow will have charge of the weather
bureau observations and will probably
work in conjunction with Mr.. ]. J. Gray,
the local forecast official at Norfolk, Va.
Their station will be taken up near the
Virginia seaport city.
j. NJ. GLENN ELECTED PRESIDENT.