New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1878-07-16
HINTS TO ASTRONOMERS.
THE NAVAL OBSERVATORY ISSUES A PAMPHLET TO
PHOTOGRAPHERS, AMATEURS AND OTHERS, WHO
WISH 10 STUDY THE ECLIPSE,


PHOTOGRAPHERS, AMATEURS AND OTHERS WHO
WISH 10 STUDY THE ECLIPSE.
10y TELEGRAPH TO THE TRIBUSE.i
WASHINGTON, July 15.-A pamphlet has been
published from the United States Naval Observa-
tory, giving suggestions which are intended to di-
rect the attention Of persons who may witness the
total solar eclipse Of July 90 and who may desire to
cooperate with the Naval Observatory in observing
some of the phenomena which in the present state
of science il is most desirable should be carefully
noted on this occasion. The pamphlet gives de-
tailed instructions how to make observations with
the naked eye as well as definite directions TO pho
toTaphers and Others who may have instrumental
equipments necessary for more careful scientific
work. The following quotations will be of general
interest:
At all places the central line OF the eclipse the fol
lowing phenomena will be during totality II the
sky is clear Wiz Just the suns last ray fades out
some glowing points OF light win start into view hang
ing upon the edge OF black and gstenng like
rubes while surrounding the whole Will be halo
whose mild radiance reminds the behoder OF the gorcs
with which painters OF old adorned the heads OF
saints The glowing points the red prOmineuees end
the halo is the corona both Of which known to
be solar appendages. The consists Of compar
avey bright inner part lying close TO the sun, sur
rounded by much fainter Of luminous matter OF
vast extent and generally Of most irregular form. Ac
curate drawings Of 1t will be exceedingly valuable. POr-
lions Of the corona may probably be seen for few
seconds both before and after the totaty.
The moons shadow should be bordered by attraction
bands and some observers claim 10 have them as
dark shadows flying over the earths surface lmmedl-
aely before and Immediately after totally. Probably
they would be most visible from emlnenoe command
ing extensive landscape and u would DE matter on
interest look for them AS the truth OF LevereTs dis
eoyery OF an apparently unexplained motion Of the peri
heliOn OF Mercury now established byond AL doubt
is important TO renew tile search-for an nraMercural
nlauet DiauetG.
Those who arc expert in sketchng may do good SER
vice by making O drawing OF the corona surroun ding
the moon during the total eclipse exact possible In
doing this IL will be necessary 10 distinguish between the
OF an optical Illusion II the corona Is very bright Will
be wen TO have at hand colOred or smoked glass
through which 10 study the object but the color must be
very light else there will be danger OF It's Obscurug all
details. Surrounding objects in aD ordinarily lighted
room ought TO be distinctly visible through It. Should
such glass used tho observer should make careful
comparison OF the coronass through IL with the
pearance IL presents to the naked eye In making pen
Gil sketch 1t will be best 10 reverse the color the dark
and the white paper the dark background OF the
sky: A.. -,
July Is, 1860, when the shadow OF the moon crossed
Hudson Bay Territory the Atlantic Ocean, Spain and
n1S WIN @ IT. s eS sHi Ia the
Irkoutsk slbers, IN longitude ll7o 32 east OF Green,
wch snd latitude b4o Ia north Its course Will at lrst
be eastnOrtheast but will gradually change TO east
and after leaving ASIA TO $50 southeast IL VIII cross
direction, little northeast OF sitka cross the
British Possessions toward the southeas and enter the
United states In Longitude ob~ west OF washington III
this country Il will sweep the western end OF
Montana Territory, the Yellow Stone National Park,
eT entering Se
New-Oreans and Galveston. IL will then pass over
most the Island OF Cuba aud Southern San Domingo
and leave the earth little southeast OF Che latter Is
land. Within this country the breadth OF the shadow
will be Ab0utl 116 miles TIE eclipse VIII be visible
as partial one over all the United States, Mexico and
British America the afternoon OF Monday, July 20
Tables and formulas for computing the times OF the
principal phases found in the American EphemeTts
for the year 1873.