The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1869-08-04

of the total phase is longest, and occurs when
the sun is highest in the heavens, and most
likely TO be free from haze and cloud.
Professor Asaph Hall, of the National Obser-
Vatory, with Professor Rogers of the Hydro
oraphic Office and others started on the first of
May for Alaska, probably Behring's Straits.
Professor Hall took with him one of the large
telescopes belonging to the University of Penn
sylyania He was in other respects completely
equipped and is expected to make a valuable
series of observations.
Professor Davidson, of the United States
Coast Survey, and party, in July arrived at
sitlSa, en- route to Clulikahats county, Alaska, to
observe the total eclipse. General Davis ex
tended every possible aid to the expedition, and
succeeded in bringing to Sitka the chief of Culi-
kahats, who promises to conduct and protect
Professor Davidson and party.
The Iowa Expeditions.
Several expeditionary corps have selected
Iowa as their ground of observation, and the
town of Burlington especially will see brisk
times this week.
In Philadelphia, large party of fifteen pho
tographers was organized by Professor Henry
Morton, of the Franklin Institute, under the
authority of Professor J. H. G. Coffin, of the
Nautical Almanac Office, and with the aid of the
governmental appropriation, started two days
ago for Burlington.
The telescopes employed for this purpose are
the High School Equatorial, of six inches aper-
ture, and nine feet focal length the Gettysburg
Equatorial, from the Pennsylvania College of
that place, also of siX-nch aperture, and eight
and a half feet focal length, and smaller but
very fine instrument of four inches aperture,
from the University of Pennsylvania. These
instruments were erected in a temporary building
put up for the purpose in West Philadelphia,
and during several weeks preceding active
operations were in progress, by day and by
night, in the adjustment of the instruments and
the practcing of operators.
The organization of the party was in accord
ance with the suggestions of Mr. Warren De la
Rue, who produced the pictures of the solar
eclipse of 1860, said to be the best of the
kind yet made. He recommended that on
the occasion of future cclipses refractOrs
of six-inch aperture and ten feet focal length
should he used, mounted on equatorial stands
with clOck-wOrl drivers. Each instrument to
have portable observatory with Photographic
appliances, including four plate-holders, and
five baths, with fused nitrate of silver, which
gives a more sensitive surface than the crys-
tallized salt. -Four operators should accompany
each telescope, twobeing expert photographers,
and all well practsed with the instrument in
making lunar photographs. 1t is estimated
from pictures of former total eclipses that the
light of the prominences have an actinic force
of about $50 times that of the full moon, and
about 900 times less powerful than that of the
sun, therefore with a telescope of siX-inch aper-
ture moderately quick, instantaneous exposure
would secure pictures of the prominences, while
perhaps from 15 to 20 seconds would be required
for the corona
This expedition omprises:-Professor Henry
Morton, Professor A. NJ. Mayer Professor G. F.
Hines, Mr. .. II. Willard, Mr.. j. Mahoney Mr.
IL. G. Phillips Mr.. o. H. Kendall, Mr., J. c.
Browne, Mr.. w. j. Baker, Mr. j. Zentmaver.
Mr.. L. Moellng, Mr. E. L. Wilson, and others
Professor E. c. Pickering, of Boston, and Pro-
fessor James McClune will also accompany the
party, to make physical and astronomical
observations.
The second party fitted out by the Naval
Observatory consisted of Professors William
Hardness and j. r. Eastman, United States
Navy, in charge of the meteorological and
astronomical work. and Dr. Edward Curtis
United States Army, under orders from the
Surgeon-General's Department, to PHOTOGRAPH
in connection with the observatory party. the
various phases of the eclipse This party is now
at Des Moines, Iowa; they have mounted their
instruments and made preliminary observations.
The "Litchfeld Astronomical Expedition of
Hamilton College, fitted out by the liberality of
Mr. Edwin G. Litchfeld, Clinton, N. Y, will
also be stationed near Des Moines, Iowa. where
the obscuration lasts nearly two minutes and
forty-fve seconds. While observations for pre-
cising the times of beginning and end will not be
neglected Cthough nowadays of comparatively
little use) the principal object will be the inves
tigation of certain questions regarding the
physical constitution of the sun and its en-
Velopes. Two larger telescopes respectively of
nine and four inches aperture will form the
centre, around which will be arranged the other
apparatus; several smaller telescopes and spy
glasses, three chronometers a spectroscope
Nicols' prism, an extensive set of glasses of va
rious colors and shades another set of photo
graphic paper etc. DIR. c. II. T. Peters. of the
Litchfeld Observatory; Professor William A.
Rogers, Frederick Hubbard and j. H. Hall form
the corps. One of the finest spectroscopes vet
made was expressly imported for this expe-
dition.
The accompanying parties are also preparing
for observations in Iowa and Illinois,
Professor j. H. c. Coffin and two assistants.
Washington, to Burlington, Iowa
DR.. B. A. Gould, Cambridge Mass; Professor
c. A. Young and one assistant, Hanover, n. II.
Professor G. F. Bracket and one assistant,
Brunswick, Me-; Miss Maria Mitchell. New
York; Professor j. A. Langley Pittsburg, Pa. ..
Professor j. NJ. Van Week, Middletown. Conn.
to Burlington or vicinity.
Professor s. Alexander, General Halstcad and
two assistants, Princeton, N. j., to Mount Plea
SAINT, or Fairfield, or Boonesboro, Iowa.
EProfessor j. G. Watson and one assistant, Ann
Arbor, Michigan, to Mattoon, Illinois,