Eagle River review. [volume] (Eagle River, Wis.) 1890-1927, 1925-01-22

sofa; Menominee and Frankfor,
Michigan; London, Ontario; Dun-.ir.
New York; Wilkes. Barre, Penn y :
! vania; and New York City north o
Central Park. Inside the no.tler
edge of the path are ManiStiq le
Michigan; Toronto, Ontario; Auburn
and Hudson, New York; and Ney
Bedford, Massachusetts. A. mile
two outside the path are Syracuse
New York; Springfield, Massachu
sets, and Providence, Rhode Island
Totally begins over Daluth
about one and one half minutes pas
eight clock, Central Standard Timt
gradually getting later until it reaci.
es Rhode Island where it begins abol.
eleven minutes later or nearly thi
Teen minutes past nine, Eastern Sta.
dard Time. Except near the northeri
and southern boundaries Of the shad
ow path, totality will last about tw
minutes. This time seems short emu
out the longest eclipse never last
much more than eight minutes, an,
good deal can be done even in tw
minutes if one is properly prepared
n the table herewith are given thei
approximate times and durations Q
lotality for few Representative
places along the shadow path.
In making these reports of totalit
Or non-totality along the edge of tn
eclipse it is necessary to be extrem
Iy precise about the exact position 0
The observer on the map and also
De very sure about whether tn
eclipse was really total at that poin
or merely almost total.
To settle the last point there ar
four tests of totaIity all of which ar
set down as questions one to four a
which should be applied by each Oh
server, as many of the four question
being answered as possible.
AS to the exact position of the oh
eryer the main thing to keep i
mind is the necessity of locating tn
position of the observer by referenc
20 some fixed and recognizable land
mark, as, for example. a well know
crossroad corner, railway junction
a public building or something of tina
Sort The distance from such lane
marks should be given to the neare
hundred feet. In cities or towns the
most convenient way to locate one
position is by reference to the neares
street corner, naming the streets.
Photographic the Corona
At least two sets of exposure
ihould be made. One of them shoul
be short, say half a second to fiv
seconds, so as to get the inner coron
close to the sun. The other set of e,
posures should be from five to twent
,econds each, to get the outer an
weaker fringe of the corona. Their
will be time for more than one
the first set if the pilates are change
rapidly by rehearsing beforehand.
portrait lenses such as Petzval dou
let, with focal length of twenty
thirty inches, will find it useful
dust it off and rig it up in Gamer
This gives larger scale than tn
more modern portrait lenses. If tn
observer has a telephone lens it ma
also be we'll used
The times of exposure should br
based on the known performance
the camera on the basis that an ey
posture Of about a quarter of sec
ond will give an image of the inne'
corona with an ordinary camera. Fo
the long exposures the sun will trai
to some extent, but this will not mat
ter as the outer part of the corons
is not very definite and the trailing
will be very minute.
Remember that you may get thu.
only picture secured of the eclipse
especially if you are situated on one
Of the western shores of the Great
Lakes where there are no smoke
clouds or buildings to interfere with
the view provided that the sun rises
clear of clouds. The following partic
ulars should be noted and reported
Cd the lens used, (2) it's focal length
CD the make of plate or film, "a tn
exposure used for each picture
you are not willing to part with tn
negative itself the committee would
like to have two good prints from
each negative. AS before, reports OF
photographs may be sent either to
the Scientific American or to the
National Research Council
The next phenomenon that may be
observed is that of the so-called shad
ow bands. This curious appearance
is often seen just before the moon
completely covers the sun.
Looking at the white side of a
house or onto big white shee'
spread over the ground one may see
little dark and bright wavy band
travelling across the surface. The
bands are usually about foot apart
and some inches wide, although not
very clearly defined. No one seems to