The times. [volume] (Washington [D.C.]) 1897-1901, 1901-05-12

which had been brought round Cape Horn
for their use. The yacht covered 5000
! herst party sailed 1900. carrying an
| equipment of delicate and valuable in
| struments and then were disappointed
because just at the critical moment there
| was bit of white cloud in the line of
the eclipse. The meteorological record of
! Sumatra is good. and under the law of
probabilities the astronomers have reason
/ to hope for a clear day on May II, but
{ there can be no assurance beyond hope
based on this fair probability.
il is. OF course. rather unusual for Il
! technical school to send a party to OBJ
serve an eclipse of the sun, whether at
/ the antipodes or nearer home. but the eN-
/ petition is, in fact, quite in line with the
recent policy of the Institute of TeChnol-
ogy Moreover, the institute has GER
tain amount of money which is available
only for special scientific research, and it
is from this fund that the expenses of
the long voyage have been betrayed in
the hope that something valuable might
be-done in the region of pure science.
The eclipse last year offered an oppor-
tunity for making observations compare
lively near home. and incidental to the
astronomical work some geOdetic work
was done. For example, in illustration
of this latter point. il was known that
the maps of the part of Georgia IN the
neighborhood of Washington were not
controlled by triangulation and ii was not
expected that the latitude and longitude
of the station could be accurately scaled
from them. Prof. Burton, therefore. made
an independent examination, obtaining
the latitude by means of an astronomical
transit and the longitude by a time sig
nal from Washington, ID. c. This deter
miuation placed the location of the observ-
ing station some four miles north and
nearly two miles west of the map loca-
ton. and.o off the central line of the eclipse
sufficiently to reduce the period of COM
puted totality about two seconds.
While the present party is prepared TO
undertake similar corrective determine
lions in Sumatra. the chief purpose is
independent astronomical work. This will
consist Of observations of the four con-
facts, namely, the first contact, when the
edge of the moon touches the edge of the
sun. the second contact, or the beginning
of totality, when the sun is first COM
pletely hidden; the third contact, or the
end of totality, when the rim of the sun
is about to emerge from the shadow; and
the last contact. when the edge of the
moon separates itself from the edge of
the sun. With the first contact q grow
ing darkness advances steadily toward
the spectator, the birds, as one writer
describes it, fly silently to their nests, and
all nature seems to take on the hush of
sudden night. a little golden rim of the
sun is visible up to the moment of the
second contact. When hat disappears
the corona. about which much has been
written by all who have described a to-
tai eclipse, seems to flash out from the
black disc of the moon with a wonderful
and almost unearthly beauty.
The corona, supposedly, is a permanent
phenomenon. but Ii is not revealed until
the last rays of the sun are hidden. There
are really two coronas. the inner corona.
which seems to surround the moon like
direct halo, and the outer corona, which
sends out faint streamers of light far into
the darkness of the heavens. What the
corona is or what its causes are nobody
knows. but the strange coronal light has
awakened the curiosity of the astronomers
of many centuries. Within comparative
ly few years ii has been possible. however.
to photograph this phenomenon. and Mr..
Smith. the photographer of the institute
expedition, has introduced novel methods
for mounting the camera and making 1t
follow the apparent motion of the sun.
with greater ease and exactness than had
before been possible so that he is hopeful
of particularly valuable and interesting re-
suits. 1t is possible also that he may un-
dertake to photograph those mysterious
waves of darkness and light which precede
totally and are called shadow bands"
This is a task not known to have ever
been undertaken although some attempts
have been made at Cambridge to study
the principles involved as illustrated in ar
tificial shadow bands produced by means
of a distant flash light.
An eclipse is such an unusual and elu-
sive phenomenon that IL is studied by
nearly every scientist who has special
physical problem on his hand. with view
to finding some tangible clue to a solu-
ton of his special difficulties. From such
a purely experimental standpoint obser-
vations in magnetic variation were made
in this country during the last eclipse by
students Of terrestrial magnetism stationed
at intervals along the path OF the shadow.
The results of the observation at that
time have been analysed by Mr. l.. A.
Bauer in charge of the magnetic work
of the United States Coast and Geodetic |
Survey. who has arrived at the conclu- |
sion that the apparent Magnetic variation, |
as shown in the dip and decliuation of a |
magnetic needle hung from silk threads, |
was not WI
canoe. While Mr. Bauer does not vet |
present a working theory he is compelled |
TO believe that the oscillation observed |
during the eclipse was not accidently con- !
nected with it, but was indeed brought |
about by some change which took place |
in the upper regions of the atmosphere, |
by the withdrawal therefrom of the suns |
rays, and has made arrangements for |
careful observation all over the world |
during the eclipse next Friday. AS the |
institute party made magnetic observa- !
tons during the eclipse, so Ii will under |
take the same work this year in Suma-
ira, and at the same time similar obser- |
vations viii be made at its geodetic Oh
seryatory In the Middlese1 FelIs near
Boston.
Another interesting piece Of work which
this party viii carry out at Sumatra.
though not directly connected with the
elipse. will consist Of measurements of
the force Of gravity by means Of the
pendulum apparatus which has been lent |
by the Coast and Geodetic Survey |
Pendulum observations Of this kind how
ever. have been made at many points
both in the United States ana in Europe
In a recent expedition to Greenland and |
Labrador, for example, Prof. Burton
made a number Of observations Of this
character. and he hopes by similar OBJ
observations in Sumatra to introduce a
link in the calculations already
made.
In preparing the present expedition
the institute has had the cooperation OF
the Harvard Observatory, through its !
director, Prof +. C. Pickering. Photo
graphic lenses and other Instruments |
have been lent to Prof Burton for the
work in Sumatra. and the plans Of a new
form Of synchronized driving clock. the
joint invention of Prof. Pickering and Mr.
w. p Gerris. of Harvard, have been
placed at his disposal. 50 that he will be
able to equip his instruments with this
device, which is, briefly an electric motor