The American Ephemeris and Nautical Almanac

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^

SDPPIEMENT TO THE AMERICAN EPHEMERIS, 1918

TOTAL ECLIPSE OF THE SUN
JUNE 8, 1918

FUBUBHBD BY THE NAUTICAL ALMANAC OTFICB,
tJ. S. NAVAL OBSERVATORY, UNDER THE AU-
THORITY OP THE SECRETARY OF THB NAVY,
SOLD BY THB SUPERINTENDENT OP D0CU1IBNT8,
GOVBRKHENT PRINTING OFFICE, WASHINOTON, D. C.
PRICE THIRTY CENTS PER COPY

WASHINGTON
GOVERNMENT PRIN11NQ OFTICB

U. S. NAVAL OBSERVATORY.

*

Capt. J. A. HooGBWEBFF, TJ. 8. N., SuperinUndetU.

ASTRONOMICAL COUNCIL.

Capt. J, A. HooGBWEBFF, U. 8. N. Prof. A. Haix, U. 8. N.
Lieut. Comdr. J. P. Mubdock, U. 8, N. Assistant AstrQjEK>nier G« A. Hill.
Prof. W. S. EiCHELBEBGEB, U. 8. N, Assistant Astronomer J. C. Hammoni>.
Prof. F. B. LnTELL, U. 8. N. Assistant Astronomer H. R. Mobga^.

DEPARTMENT OF THE NAUTICAL ALMANAC.
Prof. W. S. EiCHELBEBGEB, TJ. S. N., Director.

ASSISTANTS.

Jambs Robebtson.
William T. Cabbigan.
Abthub Snow.
Walteb M. Hamilton.
Abthxtb Newton.
Pebbz Fisgh.

Geobge F. Cbawley.
Cliffobd S. Lewis.
Joseph J. Abnaud.
Fbank Langellotti,
Reuben Weinstein.
Mobbis Lifebock.

PIECEW0RKEIU3.

Elieaheth B. Davis.
Janet McWiUiam.
Hannah F. M, HedricJc.
Alfred DooHtUe.
Henry B. Evans.

Isabel M. Lewis.

Oeorge B. Merriman.
Frank E. Ross.
Henry B. HedricJc.
Thomas E. Trott.
Louis Lindsey.

Note.— Those whose names are printed in italics devote only a small portion of their time to work of the Nautical
Almanac Office.

January, 1917.

[I

PREFACE.

The present Supplement has been prepared partly from the
tables and data given m the American Ephemeris and Nautical
Almanac for 1918 and partly from data furnished through the
courtesy of Professor ۥ F. Marvin, Chief of the U. S, Weather
Bureau. The Supplement is designed especially for use along the
path of totality in the United States, extending diagonally from the
State of Washington to the State of Florida.

In preparing the large scale drawings, Charts III and IV, the
data have been entered directly upon the map of the United States
issued by the U. S. Geological Survey.

J. A. HOOGEWERFF,

Captainy U. 8. N.y
Superintendent Naval Observatory.

Washington, January, 1917.

3

CONTENTS.

PART I-METEOROLOQICAL DATA.

Page.
Table I — ^Average Weather Ck>nditioii8 in June for VariouB Stations in the United

States Along the Path of the Eclipse 9

Table II — Percentage of Sunshine During the First 15 Days of June for Various Sta-
tions in the United States Along the Path of the Eclipse 10

Table III — Prevailing Direction from Which the ^ffmA Blows During the First 15
Days of June, for Various Stations in the United States Along the Path of the

EcUpse 10

Table IV— Average Hourly Wind Velocity, in Miles, During the First 15 Days of June,

for Various Stations in the United States Along the Path of the Eclipse. 11

Table V— Mean Temperatures from June 6 to June 10, Inclusive, for Various Stations

in the United States Along the Path of the Eclipse 11

PART II—ASTRONOMICAL DATA AND CHARTS.

Explanation and Use of the Tables 15

Table VI — ^Elements and Circumstances 23

Table VII— Besselian Elements 24

Table VIII— Piith of the Total Phase 25

Table IX— Path of the Total Phase in the United States ...... 26

Table X — ^Reductions for Points Not on the Central line, to Obtain Times of Contacts 28

Table XI — ^Reductions for Points Not on the Central Line, to Obtain Position Angles 30

Table XII— Local Circumstances at 78 Cities 31

General Chart of the EcUpse Chart I

Chart of the Sky in the Vicinity of the Eclipsed Sun Chart II

Chart Showing Path of Total Eclipse Across the Western States Chart III

Chart Showing Path of Total Eclipse Across the Eastern States Chart IV

6

PARTI.

METEOROLOGICAL DATA FURNISHED BY THE

U. S. WEATHER BUREAU.

TOTAL ECLIPSE OF THE Sim, JUNE 8, 1918. 9

TABIiE I.

AVERAGE WEATHER CONDITIONS IN JUNE.

StAtlon.

Washington:

FortSimcoe . . .

Queets Elver . .

Seattle . . . .

Sixprong . . . .

Tftcoma . . . .

Oregon:

Baker . . . . .

La Grande . . .

Pendleton . . ,

Idaho:

Boise City . .
Cambridge . .
Bbiley. ...
Pienon ...
Pocatello ...

Wyoming:

Alton ....
Eden ....
Encampment .

Ck>lQrado:

Gol(»rado Springs
Denver . . .
Las Animas . .
Pueblo . . .
Steamboat Springs

Kansas:

Ashland . . .
CooUdge ...
Dodge City . .

Oklahoma:

Holdenville .
Okeene . . .
Oklahoma City .

Eleva-
ttoii.

Fed.

1427

16

248
1100

213

3471

2784
1070

2739
2739
5347
7000
4483

6200
6577
7322

6098
5272
3899
4734
6701

1951
3348
2513

900
1194
1247

Temper-
ature.

64.5
55.4
60.1
67i)
59.4

58.6
59.7
64.3

66.0
68.6
58.9
50.9
64.2

55.0
56.3
57.9

63.3
66.4
72.3
69.0
55.8

75.2
72.1
73.1

75.5
76.9
75.7

Precipi-
tation.

0.45
4M
1.72
0.61
2.13

1.21
1.59
1.01

0.88
1.09
1.00
1.19
0.99

1.51
1.18
0.94

1.97
1.47
1.40
1.47
1.62

3.54
2.21
3.32

4.36
3.79
3.07

Peroent-
ageof
Clear
Days.

63
33
27
53

27

33
50

47

43
53
33
50
50

27
40
30

43
40

47
43
70

57
50
43

80
73

47

Peroent-
ageof
Bainy
Days.

7

80
83
13
30

27
27
20

20
23
23
17
20

27
23
30

27
27
10
23
27

27
20
30

20
30
27

Note.— These averages are based upon obserrations for periods of 5 to 30 or more years.

Days on wbicb the rainfall amoonts to one lumdredtli of anindi or more are regarded as rainy days.

10 TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918.

TABLE II.

PERCENTAGE OF SUNSHINE DURING THE FIRST 15 DAYS OF JUNE.

"" '*

TinbB.

LoGAlStendardTiiiM.

A.M.

P.M.

oOKion.

»k-10^

lofc-iik'iiMak

12^1k

ik-ak

ak-3k

3k-|k

66
51

5fc-«fc

Seattle, Wash.
Baker, Oreg.

Pacific
Pacific

54

81

64
84

69
86

79
84

77
80

75

70

70
61

58
44

Boise City,. Idaho
Pocatello, Idaho
Denver, Colo.
Pueblo, Colo.

Mountain
Mountain
Mountain
Mountain

88
78
83
86

•

92
82

84
89

94
84
82
89

93
79
73

87

91

78
72
88

85
71
65
80

85
60
59
71

80
54
49
63

75
46
44
54

Dodge City, Kans.
Oklahoma City, Okla.

Central
Central

73
81

81

84

83
85

85
83

86
83

86
81

83
76

77
74

67
59

NoTB.— These avenges are based upon obeervatioiis lor ttie five years 1911-1915, exeepb tbat those for Dodge City
are based upon observatioiis for the ten years 1906-1915.

TABLE m.

PREVAILING HOURLY WIND DIRECTION DURING THE FIRST 16 DAYS OF JUNE.

Btatkm.

Time.

Local Standard TimA.

A. M.

P.M.

9k-i0k

10«»-11>»

ll*-12k

12h-lh

lk-2h

2»'-3»»

NW.
NW.

4»»-5k

6»^k

SeaUle, Wash.
Baker, Oreg,

Pacific
Pacific

S.

N.

NW.

N.

NW.

N.

NW.

N.

NW.

N.

W.

NW.

N.
NW.

N.
N.

Boise City, Idaho
Pocatello, Idaho
Denver, Colo.
Pueblo, Colo.

Mountain
Mountain
Mountain
Mountain

SE.
SW.
SE.

• •

SW.

NE.
SE.

• •

W.

NE.
SE.

NW.
SW.
NE.
SE.

• •

W.

NE.
SE.

• •

SW.

NE.
SB.'

« •

SW.
B.

SE.

SW.
SE.
SE.

• •

SW.

NE.
SE.

S.

s.

Dodge City, Kans.
Oklahoma City, Okla.

Central
Central

S.

s.

S.

s.

S.
S.

S.

s.

S.

s.

S.

s.

S.
S.

S.

s.

Note.— These averages are based upon observations for the five years 1911-1915, except that that for Boise City !<(
based upon observations for the five years 1882-1886.

TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918. 11

TABLE IV.

ATEBAOE HOUBLY WIND VELOCITY IN MILES DURING THE FIRST 15 DAYS OF

JUNE.

8tiktioii.

Ttsob.

Local Standard TiiDA.

A.M.

P.

M.

»k-10^

lOfc-llk

iiMak

lak-lk

ik-ak

»^

3«Mk

4^-eM

5k-6k

Seatae, Wash.
Baker, Oreg.

Pacific
Pacific

9
6

9
6

9

7

10

8

10
8

10

8

11

8

11

8

11

7

Boise City, Idaho
Pocatello, Idaho
Denver, Colo.
Pueblo, Colo.

Mountain
Mountain
Mountain
Mountain

6
8
8
6

7
8
9

7

8

8

10

8

8

9

11

9

8

9

11

10

8

9

11

11

9

10
11
11

8

9

11

11

8

9

10

11

Dodge City, Kans
Oklahoma City, Okla.

Central
Central

14
16

14
16

14
16

14
16

14
16

14
16

15
16

16
16

14
15

NOTX.— Theae avecagea are based upoo obaeiTatioos for the Ave yean 1911-1915.

TABLE V.

MEAN HOURLY TEMPERATURES FROM JUNE 6 TO JUNE 10, INCLUSIVE.

station.

Time.

Local Standard Time.

P.

u.

12k-lk

lk.2k

2k-«k

3k-4k

4h^h

5»»-6k

Seattle, Wash.
Baker, Oreg.

Pacific
Pacific

e

61
66

•

63
67

64
67

e

64
66

e

63

65

o

62
64

Boise City, Idaho
Pocatello, Idaho
Denver, Colo.
Pueblo, Colo.

Mountain
Mountain
Mountain
Mountain

68
69
71
74

70
70
72
75

70
69
71
76

70
69
71
76

71
68
70
75

70
66
70

74

Dodge City, Kans.
Oklahoma City, Okla.

Central
Central

75

81

77
82

78
83

78
83

77
83

76
81

Note.— Theae averages are based upon obaervatlaoa for the five yean lOll-lOlA.

=3

PART 11.

ASTRONOMICAL DATA AND CHARTS.

13

EXPLANATION AND USE OF THE TABLES.

The Elements of the Eclipse, given in TaUe VI, are for the moment of
conjunction of the Sun and Moon in right ascension, but the remaining data
and tables are computed for the d^utct positions of these bodies at the several
instants referred to.

The Circumstances of the Eclipse, given in Table VI, are as follows:

The line entitled "Eclipse b^ins" gives the Greenwich mean time at
which the Moon's penumbra first touches the Earth, together with the latitude
and longitude of the point of contact.

The line entitled "Central eclipse begins" gives the time when the axis of
the Moon's shadow first touches the Earth, together with the latitude and
longitude of the point of contact.

The hne entitled "Central ecKpse at local apparent noon" gives the time
when the axes of the Earth and of the shadow cone lie in the same plane,
together with the latitude and longitude of the point where the axis of the
shadow cone then cuts the Earth's surface.

The lines entitled "Central eclipse ends" and "Eclipse ends" give, respec-
tively, the times when and the localities where these events occur, the phe-
nomena being the converse of those denoted by the similar phrases for the
beginning.

Table VII contains the BesseHan Elements, or the data from which accu-
rate times of the phases may be computed for any station whose coordinated
are known.

Tables VIII gives the latitude and longitude of points along ihe central
line, and also of corresponding points on the northern and southern limits of
the path of total phase for which mid-totality occurs at the ^loment indicated
in the first column. The final column gives the duration of totality at the
points on the central line.

Table IX gives, for each degree of longitude from 80° to 125° west from
Green^ch, the latitude of points on the northern limit, central line, and south-
em limit, of the path of total phase. It also gives for each of these points
on the central line the Greenwich mean times of the four contacts, the position
angles from the north point and from the vertex, the duration of totaity, the
Sun's altitude at mid-totahty, and the shortest distance to the edge of tlie path.

Tables X and XI give reductions for obtaining the times of contacts and
the position angles for points in the path of the total phase but not on the
central line.

Table XII gives the local circumstances at 73 cities scattered throughout
the United States, and at Honolulu, Juneau, Nome, Panama, and San Juan.

Chart I gives a general outline of the whole ecUpse.

15

16 TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918.

Chart n gives the planets and stars in the vicinity of the eclipsed Sun.

Charts III and IV give, on a much larger scale than Chart I, the path of
total eclipse, the first in the Western States and the other in the Eastern States.
This path is crossed by a series of straight lines, which terminate in the northern
and southern limits of totality, each line being approximately the locus of
all points for which mid-totality occurs at the moment of Greenwich mean
time indicated thereon. These charts contain also two series of long curved
broken lines, each of the one series including all points for which the beginning
and each of the other series including all points for which the ending of partial
eclipse occurs at the moment indicated* Chart III contains, in addition,
symbols indicating the probable meteorological conditions at the time of mid-
eclipse for eight stations situated in or near the path of totality.

RIGOROUS COMPUTATION OF THE TIMJES.

An accurate determination of the several phases as visible at any par-
ticular station may be obtained from the Besselian Elements which are given
in Table VII for every ten minutes of Greenwich time. Their geometric
signification is as follows:

Let us imagine a plane passing throu^ the center of the Earth, perpen-
dicular to the right line joining the centers of the Sim and Moon. This latter
line is the axis of the Moon's shadow, and the plane is called the fundamental
plane or plane of xy. We take the intersection of this plane with that of the
Earth's equator as the axis of x, and the center of the Earth as the origin of
coordinates. The axis of y is perpendicular to that of «, and directed toward
the north; x and y are then the coordinates of the point in which the axis of
the shadow intersects the fundamental plane, and they are here expressed in
terms of the Earth's equatorial radiiis as unity. The angle d, of which the
sine and cosine are both given, is the declination of that point of the celestial
sphere toward which the axis of the shadow is directed; or, in other words,
it is the declination of the center of the Sun as seen from the center of the Moon.
The angle m is the Greenwich hour-angle of this same point of the celestial
sphere.

The quantities l^ and Z, are the radii of the shadow cones upon the funda-
mental plane, Zj, corresponding to the penumbra, and Z, to the umbra. The
notation is that of Chauvenet's Spherical and Practical Astrcmomy, in which
I2 is regarded as positive for an amiular and negative for a total ecUpse.

The angles/, and/,, the tangents of which are given, are the angles which
the elements of the respective shadow cones make with the axis of the shadow ;
or, they are the semiangles of the two cones.

In order to f aeiUtate interpolation to any required moment, the logarithms
of x'r y\ and /*', which are the changes of a;, y, and m> ia one minute of time,
are given at the bottom of the table.

The method of computing an eclipse from its Besselian elements is based
on the fact that the distance of the observer from the axis of the shadow cones
is equal to the radius of the penumbra at the point of observation for the begin-
ning and ending of the ecUpse, and is equal to the radius of the umbra at the

)iiii

m

m

ie

i

i"

CI

c

TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918. 17

:\

i

03,

da-
rk

ifli-
iw;

ms

les
in-
he

point of observation for the beginning and ending of totality or of the annular
phase. To find this distance and radius in each case, we proceed as follows:

(1) The coordinates of the observer, f, iy, and f, together with their varia-
tions in one minute, are computed for some assumed moment of Greenwich
mean time, as near as practicable to the true time of the required phase.

(2) The coordinates x and y of the axis of the shadow, together with their
variations in one minute, are taken for the same moment from the tables of
elements.

(3) From (1) and (2) the position and motion of the observer relative to
the axis of the shadow are found.

(4) The radius of the penumbra or umbra at a distance from the funda-
mental plane equal to that of the observer is also computed.

(5) Then, assuming the motions to be imiform, we determine the time
required for the observer to be brought to a distance from the axis of the
shadow equal to this radius.

The formulae and directions for the several steps in the computation are
as follows:

(1) Find p cos <p' and p sin <p', which are the geocentric coordinates of
the station referred to the Earth's equator, p being the distance from the
center of the Earth and <p' the geocentric latitude. These coordinates may be
computed from the following table based on the compression of the Earth
adopted at the Paris CJonference of 1911, 1/297, by the formula —

pC0fl^-^C08^

. sin ^
p sin y ■» >j •

ip being, as usual, the ge<^raphic latitude.

TabUfor ComptUirig the Oeoeentric Coordinates of a Place,

¥>

LogF.

LogG.

0**

5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90

0.00000

0.00001

0.00004

0.00010

0.00017

0.00026 *

0.00037

0,00048 ^

0.00060

0.00073

0.00086 2

0.00098

0.00110

0.00120

0.00129

0.00137

0.00142

0.00145

0.00146

0.00293

0.00292

0.00289

0.C0283

0.00276

0.00267 *

0.00266 ■■

0.00245 "

0.00232

0.00220

0.00207

0.00195

0.00183

0.00173

0.00164 *

0.00156

0.00151

0.00148

0.00146

79597°— 17-

^

18 TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918.

For the assumed Greenwich mean time of computation, take from the
tahle of elements the values of sin d, cos df and il. Then, with X for the longi-
tude west from Greenwich, the coordinates of the observer will be —

{-p cos i/ sin (m-X)

>-p sin i/ COB d-p COB */ wad cos (M-X)-iy,-iy2
J'-'p flin ^^ Bin cf+p COB </ cos d cos (M-X)-ri+r2

and their variations in one minute of mean time will be —

^'- [7.63992] p cos • cos (/i-X)

i/- [7.63992] p COB • sin d sin (m-X)- [7.63992] { sin <f

^^ is not needed.

(2) For the same assimied moment of Greenwich mean time, take from
the tables of elements the coordinates x and y of the axis of the shadow, together
with their variations for one minute, which are/ equal to one-tenth of the
differences of two consecutive numbers. These variations are represented by
x' and y', and their logarithms are given beneath the tables of x and y.

(3) *rhe distance m and position-angle M of the axis of the shadow rela-
tive to the observer, and the relative motions, n and iV, are computed by the
formulae — m sin if-x-^

m cos M'^y—rj
n sin N^a/-^^
n cos N^y^-n^

(4) Both for the umbra and for the penumbra, the radius L at the dis^
tance f from the fundamental plane is computed by the formulae —

Z-Z-ftan/

Z and /being taken from the table of elements, and f computed in (1).

(5) If the time chosen for computation is exactly that of the beginning or
ending of the ecHpse, we shaJl have —

But, as this condition will rarely be fufilled on a first trial, a correction r to
the assumed time is computed thus: Find the angle ^ from the equation —

„. , m sin (M-N)

sin ^'— ~ _

JLi

There will be two values for this angle; the one for which cos ^ is negative
must be taken for the beginning of the edipse, or for the ending of the total
phase, but the one for which cos ^ is positive must be taken for the ending of
the edipse, or for the beginning of the total phase. The correction r to the
assimied time will then be found, in minutes, from —

m cos (M—N)L cos if/
n n

However, only in case the value of t does not exceed a few minutes can
the time thus corrected be considered even fairly accurate. Therefore it is
best to commence the computation by assuming times near the phenomena
wanted. The times for the beginning and the ending of an ecUpse may be
derived from Chart I with sufficient exactness, the time for the total phase
may then be assumed as midway between the times assumed for the b^inning
and the ending of the echpse; or, in case of a partial ecUpse, this time midway
may be assumed as that of the maximum eclipse.

TOTAL ECLIPSE OF THE SUN, JTmS 8, 1918. 19

The more acciirate times resulting from the computation as outlined above
and as illustrated in the example below may now be taken in place of those
originally assumed, and the whole computation may be repeated, thus leading
to a Yalue of r in each case, which should be very small, and which should
give a very accurate time of the phenomenon. Such a repetition of the com-
putation will be advisable, moreover, for the reason that it will enable one to
locate and eliminate any accidental numerical errors that may have occurred
in the first computation.

As a result of this last approximation the computed times of contact will
be theoretically exact within less than a second, but the uncertainties of the
solar and lunar taUes are such that an unavoidable error of several seconds
may exist in the prediction.

K the given station is f oimd upon Chart III or PV, the tim^ of b^inning,
ending, and mid-totality may be taken from the chart to the nearest minute,
and a second computation wiU be imnecessary imless desired as a check upon
the accmracy of the numerical work.

Positionrangle qf Point of OorUdct. — ^The position-angle P, of the point of
contact, reckoned from the north point of the Sun's limb toward the east, is
foimd by the formula —

where the results of the last approximation are used.

The position-angle V, of the point of contact, reckoned from the vertex
of the Sun's limb toward the east, is found by the formula— ,

y-p-c
where C is obtained from

tanC-i

sin C having the same algebraic sign as {> and again the results of the last
approximation are used.

Time of Maximum Eclipse. — ^For a partial eclipse, or for a c^atral ecUpse
at a point at which the eclipse is only partial indicated by sin ^ greater than
unity for the umbra, the correction to the assumed time to obtain the time of
maximum eclipse is given by the formula —

mcoe(M-N)
n

Magnitude of the Maximum Eclipse. — This is given by the formula^ —

D* ^"^^

2L-0.5446

where A= ±m sin {M— N), always taken positive, and L is the radius of the
penumbra. D is, in all cases, the ratio to the Sun's diameter of the straight
Une passing through the centers of the two disks and having for ita extremities
the Sun's limb that is nearest to the Moon's center and the Moon's limb that
is nearest to the Sun's center. In a partial eclipse D is the fraction of the
Sun's diameter covered by the Moon.

*Si2ioe, in obtaining this formula, the angles of the two shadow cones are considered the same, the value obtained
therefrom should be increased by zh^h of itselt

20 TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918.

Oomputatian of the Solar Eclipse of June 8, 1918, for Den/ver, Colo.
The position of Denver is —

Latitude, «»- + 39 40 36
Longitude, X- +104 56 56

and its geocentric coordinates are —

p ain ^-9.80280
p COS •-9.88689

From the eclipse chart we find the approximate times of the phases to be —

d h m
Beginning June 8 10 10

T Junes

M

X

logp COS «/

log sin (m-X)
log^
log cos (f
log p sin 4/
log sin e?

log'?!
logTi
log sin (f
log p cos •
log cos (m-X)
log cos (f
logih

log r«

r.
r

log p COS •

log COS (m-X)
log const.

log€
log sin (f

log!'

logi?'

X

• . ■ ■

Middle
Ending

Ba^iimiiig. Middle.
10»» 10" IP 20-

>>

i»

8 11 20
8 12 30

Bnding.
12»» 30«

152 48 30 170 18 24 187 48 24
104 56 56 104 56 56 104 56 56

47 51 34 65 21 28
9.88689 9.88689

9.87011
9.75700

iF.ilo4o4
9.80280
9.58899
9.76734
9.39179

9.58899
9.88689
9.82669
9.96454
9.30257
9.67812

+0.58525
-0.20071
+0.24648
+0.47657
+0.72305

9.88689
9.82669
7.63992
9.75700
9.58899
7.35350
6.98591

+0.02408
+0.57148
-0.54740

+0.46574
+0.38454
+0.08120

9.95853
9.84542

9.96453
9.80280
9.58907
9.76733
9.39187

9.58907
9.88689
9.62008
9.96453
9.09604
9.47150

+0.58524

82 51 28

9.88689
9.99662
9.88351

9.96451
9.80280
9.58915
9.76731
9.39195

9.58915
9.88689
9.09459
9.96451
8.57063
8.94599

+0.58521

-0.12475 r-0.03721
+0.24653 +0.24658

+0.29614
+0.54267

9.88689
9.62008
7.63992
9.84542
9.58907
7.14689
7.07441

+0.67310
+0.70052
-0.02742

+0.46362
+0.46049
+0.00313

+0.009273 +0.009273 +0.009269

+0.002257 +0.001402 +0.000418

. .+0.007016 +0.007871 +0.008851

-0.000027 -0.000034 -0.000041
+0.000968 +0.001187 +0.001296
-0.000995 -0.001221 -0.001337

+0.08831
+0.33489

9.88689
9.09459
7.63992
9.88351
9.58915
6.62140
7.11258

+1.32200
+0.76473
+0.55727

+0.46098
+0.54800
-0.08702

Greenwich Mean Time.

Begtoning.
ogmsinlf 9.73830n
og sin or cos If 9.99527n
og m cos if 8.90956
og tan if 0.82874n

og n sin JV 7.84609
ogsinorcosiV 9.99567

6.99782n
0.84827n

ogncos iV
ogtan N

Middle.
8.43807n
9.99719n
7.49554
0.94253n

7.89603
9.99484
7.08672n
0.80931n

Ending.
9.74607
9.99477
8.93962n
0.80645n

7.94699
9.99510
7.12613n
0.82086n

n

ft

II

M

N
M-N

logm
logn

logr
log tan/
log r tan/

I

L
logm

278 26 16 276 30 43

98 4 18 98 49 4

180 21 58 177 41 39

9.74303
7.85042

9.85917
7.66328
7.52245

+0.54220
+0.00333
+0.53887

9.74303

logBin(Jf-i\r) 7.80549n
colog L 0.26851

log sin ^ 7.81703n

8.44088
7.90119

9.73454
7.66111
7.39565

-0.00358
+0.00249
-O.00607

8.44088
8.60459
2.21681n
9.26228n

98 52 31

98 35 24

17 7

9.75130
7.95189

9.52491
7.66328
7.18819

+0.54240
+0.00154
+0.54086

9.75130
7.69714
0.26691
7.71535

II

180 22 34

1.89261

I

n

log m/n
log cos (if-iV) 9.99999n

1.89260n

9.73149

log(l)

logL
log cos 4^
colog n
log (2)

-(1)
+<2)

-10 32 26
190 32 26

0.53969

9.99965n

0.53934n

7.78319n

(

ti

+0 17 51

9.99999n(±)9.99261
2.14958 2.09881
1.88106n(qF)9.87461

+78.090
-76.043

m
+2.047

+3.462
=F0.749

f +2.713 1
1 +4.211 J

1.79941
9.99999
1.79940

9.73309
9.99999
2.04811
1.78119

-63.009
+60.421

m
-2.588

d h m
r 8 10 10

d h m
r+r 8 10 12.047

I

d. h m
8 11 20
d h m
8 11 22.713

8 11 24.211

1

d h m
8 12 30

d h m
8 12 27.412

TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918. 21

Taking the four times just founds a new computation is made in each case.

The times resulting from the new computation are—

Greenwich Mean Time,
d h m 8
Begmning of the eclipse June 8 10 12 2.7

Beginning of total eclipse 11 22 42.7

Ending of total eclipse 11 24 11.4

Ending of the eclipse 12 27 24.2

Local Mean Time,
h m a

3 12 15.0

4 22 55.0

4 24 23.7

5 27 36.5

The values from the last approximation of the quantities needed in com-
puting the position angles, and the computation of these position angles, are —

1st Contact.

2d Contact.

3d Contact.

4th Contact

log^

9.76048 9.84774

9.84899

9.88286

logiy

9.58718 9.66626

9.66792

9.73612

log tan C

0.17330 0.18148

0.18107

0.14674

N

98.11 98.82

98.83

98.61

^

180.34 -10.62

190.54

0.27

P

278.45 88.20

289.37

98.88

C

56.14 56.64

56.61

54.50

V

222.3 31.6

232.8

44.4

le magnitude of greatest eclipse is obtained

as follows: —

T

11^20^

I +0.5423

Z-A

+0.5387

logf

9.7345

r tan/ +0.0025

2L-0.5446

+0.5350

log tan/

7.6633

L +0.5398

D

1.007

log r.tan/

7.3978

A +0.0011

1/400 2)
Magnitude

.003
1.01

TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918. 23

TABLE VI.

ELEMENTS AND CIRCUMSTANCES.

ELEMENTS OF THE ECLIPSE,

d h m 8
Greenwich mean time of 6 ^^ right ascension, June 8 10 7 24.2

h m t 8 8

Sun and Moon's B. A. 5 4 39.98 Houriy motions 10.33 and 152.10

Sun's declination +22 50 23.8 Hourly motion + 13.6

Moon's declination +23 17 39.1 Hourly motion + 7.4

Sun's equa. hor. parallax 8.7 Sun's true semidiameter 15 45.3

Moon^s equa. hor. parallax 58 39.4 Moon's true semidiameter 15 58.2

CIRCUMSTANCES OF THE ECLIPSE,

Greenwich Mem Longitude from

Time. Greenwich. Latitude.

d h m • ' • '

Eclipse begins June 8 7 29.0 -150 20 +16 22

Central eclipse begins 8 8 32.2 -129 58 +25 41

Central eclipse at local apparent noon 8 10 7.4 +152 10 +50 51

Central eclipse ends 8 11 42.9 + 74 31 +25 2$

Eclipse ends 8 12 46.2 + 94 53 +16 3

/

f

24 TOTAL ECLIPSE OP THE SUN, JUNE 8, 1918.

TABLE Vn.

BESSELIAN ELEMENTS.

Qreeawlcli
Mean Time.

Ckxvdinate

or Shad

Fnndamei]

B of Center
low on
itflj Plane.

Direction of Axis of Shadow.

Fa

dios of Penumbra
and Umbra on
Ddamental Plane.

kW A AV^I^V*

X

f

JjogBbii

Jjogcmi

i>

li

h

h m
7 20

-1.55216

+0.46880

+9.58880

+9.96458

110 18.6

+0.64179

-0.00410

30

1.45946

0.46870

9.58881

9.96457

112 48.6

0.64182

0.00407

40

1.36674

0.46860

9.58882

9.96457

115 18.6

0.64186

0.00404

60

1.27403

0.46848

9.58883

9.96457

117 48.5

0.64188

0.00402

8

-1.18132

+0.46835

+9.58884

+9.96457

120 18.5

+0.64191

-0.00399

10

1.08860

0.46821

9.58885

9.96457

122 48.5

0.54193

0.00396

20

0.99588

0.46806

9.58887

9.96456

125 18.5

0.64196

0.00394

30

0.90316

0.46790

9.58888

9.96456

127 48.5

0.54199

0.00391

40

0.81044

0.46773

9.58889

9.96456

130 18.5

0.64201

0.00389

50

0.71772

0.46755

9.58890

9.96456

132 48.5

0.64203

0.00386

9

-0.62499

+0.46736

+9.58891

+9.96456

135 18.5

+0.64206

-0.00384

10

0.53227

0.46716

9.58892

9.96455

137 48.5

0.54208

0.00382

20

0.43954

0.46695

9.58893

9.96455

140 18.5

0.54210

0.00379

30

0.34682

0.46673

9.58895

9.96455

142 48.6

0.64213

0.00377

40

0.25409

0.46650

9.58896

9.96455

146 18.6

0.54216

0.00376

50

0.16137

0.4(3626

9.58897

9.96455

147 48.6

0.54217

0.00373

10

-0.06864

+0.46601

+9.58898

+9.96454

150 18.6

+0.64219

-0.00371

10

+0.02408

0.46574

9.58899

9.96454

152 48.5

0.64220

0.00369

20

0.11680

0.46547

9.58900

9.96454

156 18.6

0.64222

0.00368

30

0.20952

0.46519

9.58901

9.96454

157 48.6

0.64224

0.00366

40

0.30224

0.46489

9.58903

9.96454

160 18.5

0.64226

0.00364

50

0.39496

0.46459

9.58904

9.96453

162 48.6

0.64227

0.00362

11

+0.48768

+0.46428

+9.58905

+9.96453

165 18.4

+0.64^9

-0.00361

10

0.58039

0.46395

9.58906

9.96453

167 48.4

0.64230

0.00359

20

0.67310

0.46362

9.58907

9.96453

170 18.4

0.64232

0.00358

30

0.76581

0.46327

9.58908

9.96453

172 48.4

t).64233

0.00357

40

0.85852

0.46292

9.58909

9.96452

176 18.4

0.54235

0.00366

50

0.95122

0.46255

9.58911

9.96452

177 48.4

0.54236

0.00364

12

+1.04392

+0.46217

+9.58912

+9.96452

180 18.4

+0.54237

-0.00363

10

1.13662

0.46179

9.58913

9.96452

182 48.4

0.54238

0.00362

20

1.22931

0.46139

9.58914

9.96452

185 18.4

0.54239

0.00351

30

1.32200

0.46098

9.58915

9.96451

187 48.4

0.54240

0.00350

40

1.41469

0.46056

9.58916

9.96451

190 18.4

0.54241

0.00349

m

+1.50737

+0.46014

+9.58917

+9.96451

192 48.4

+0.54242

-0.00348

Greenwich
Mean
Time.

Logx*

for

1 Minute.

Logf
for

1 Minute.

Log/*'
for

1 Minute.

Log Tangents of Angles of Cones.

Penumbi

-a.

Umbra.

h m
7

+7.9671

-4.8591

+1.1761

+7.6632

19

•

+7.66112

8

7.9672

5.1261

1.1761

7.6632

!9

7.66112

9

7.9672

5.2907

1.1761

7.6632

8

7.66112

10

7.9672

5.4103

1.1761

7.6632

8

7.66111

11

7.9672

5.5041

1.1761

7.6632

8

7.66111

12

7.9671

5.5813

1.1761

7.6632

8

7.66111

13

+7.9670

-5.C

^472

+1.1761

+7.6632

8

+'

7.66111

TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918. 25

TABLE Vm.

PATH OP THE TOTAL PHASE.

NoitlMni Limit.

Central Line.

Soatbern Limit.

Duration

Qreen-

of Total

widi
MMn
Time.

LaUtade.

Loogitiide

from
Qnenwich.

Latitude.

Loogitade

from
Greenwich.

Latitude.

Longitude

from
Greenwich.

Phase on

Central

Line.

• /

• /

• /

• /

• /

• /

m s

Tamits.

+25 55

-129 47

+25 41

-129 58

+25 27

-130 9

....

8*»36"

31 2.6

140 55.8

31 6.8

141 54.8

31 9.4

142 51.6

1 2.9

40

34 50.5

148 47.9

34 44.9

149 32.5

34 38.6

150 16.5

1 15.3

45

37 26.8

154 12.9

37 16.8

154 53.2

37 6.3

155 33.0

1 24.6

50

39 31.8

158 40.9

39 18.8

159 18.7

39 5.3

159 56.0

1 32.4

55

41 17.5

162 37.8

41 2.0

163 13.8

40 46.1

163 49.1

1 39.3

9

+42 49.2

-166 15.7

+42 31.6

-166 49.8

+42 13.7

-167 23.4

1 45.4

5

44 10.0

169 40.6

43 50.5

170 13.2

43 30.7

170 45.1

1 51.1

10

45 21.6

172 57.1

45 0.4

173 28.0

44 39.0

173 58.2

1 56.2

15

46 25.1

176 7.8

46 2.4

176 36.8

45 39.5

-177 5.1

2 0.8

20

47 21.4

-179 14.5

46 57.4

-179 41.4

46 33.1

+179 52.3

2 4.9

25

48 11.1

+177 41.5

47 45.9

+177 16.8

47 20.4

176 52.7

2 8.7

30

+48 54.6

+174 39.2

+48 28.3

+174 17.0

+48 1.7

+173 55.2

2 12.0

35

49 32.1

171 38.0

49 4.8

171 18.3

48 37.4

170 59.1

2 14.8

40

50 4.0

168 37.4

49 35.8

168 20.5

49 7.5

168 3.9

2 17.3

45

50 30.2

165 37.0

50 1.4

165 23.0

49 32.4

165 9.3

2 19.3

50

50 50.9

162 36.8

50 21.5

162 25.8

49 52.1

162 15.0

2 20.9

55

51 6.3

159 36.5

50 36.5

159 28.7

50 6.6

159 21.0

2 22.0

10

+51 16.2

+156 36.2

+50 46.2

+156 31.6

+50 16.1

+156 27.1

2 22.7

5

5120.9

153 36.0

50 50.8

153 34.6

50 20.6

153 33.2

2 23.0

10

51 20.3

150 35.8

50 50.2

150 37.6

50 20.0

150 39.4

2 22.8

15

51 14.3

147 35.7

50 44.4

147 40.8

50 14.5

147 45.7

2 22.2

20

51 3.1

144 35.8

50 33.5

144 44.1

50 4.0

144 52.1

2 21.2

25

50 46.6

141 36.2

50 17.5

141 47.5

49 48.3

141 58.5

2 19.7

30

+50 24.6

+138 36.7

+49 56.1

+138 51.0

+49 27.6

+139 4.8

2 17.8

35

49 57.2

135 37.4

49 29.5

135 54.4

49 1.7

136 11.0

2 15.4

40

49 24.2

132 37.9

48 57.4

132 57.5

48 30.5

133 16.7

2 12.7

45

48 45.6

129 37.9

48 19.8

130 0.0

47 53.9

130 21.6

2 9.5

50

48 1.0

126 37.1

47 36.4

127 1.4

47 11.6

127 25.1

2 5.9

55

47 10.3

123 34.6

46 47.0

124 1.0

46 23.4

124 26.7

2 1.9

11

+46 13.1

+120 29.6

+45 51.2

+120 57.8

+45 28.9

+121 25.4

1 57.5

5

45 8.7

117 20.7

44 48.3

117 50.6

44 27.6

118 19.9

152.7

10

43 56.4

114 6.0

43 37.8

114 37.5

43 18.6

115 8.3

147.4

15

42 35.1

110 42.9

42 18.2

111 15.8

42 1.0

HI 48.1

141.6

20

41 2.9

107 7.4

40 48.1

107 41.7

40 32.8

108 15.5

1 35.2

25

39 16.8

103 12.9

39 4.4

103 48.8

38 51.6

104 24.3

1 28.2

' 30

+37 11.7

+ 98 47.8

+37 2.2

+ 99 25.9

+36 52.4

+100 3.4

1 20.3

35

34 35.9

93 26.7

34 30.6

94 8.5

34 24.7

94 49.6

1 11.0

40

30 51.0

85 43.9

30 54v5

86 37.8

30 5C.7

87 30.0

58.7

limitB.

+25 35

+ 74 20

+25 23

+ 74 31

+25 11

+ 74 41

• . . •

26 TOTAL ECLIPSE OF THE SUN, JimE 8, 1918.

TABLE IX.

PATH OF TOTAL PHASE IN THE UNITIBD STATES.

L^tudA of Pointi on-

Data lor Pointi OA Cflirtisl Line.

Looci-
tude

First Contact.

Second Contact.

West

Northern
Limit.

Central
Line.

Soathem
Limit.

from
Qreen-
wich.

Qreenwidi

Angle
East

Angle
East

Oreenwidi

Angle
East

Angle
East

Mean Time.

fromK.

from

Mean Time.

fromN.

from

Point.

Vertex.

Point.

Vertex.

a

• /

• /

• /

h m s

•

o

h m s

•

•

80

28 8.8

27 49.3

27 30.2

10 44 14

279

213

11 41 57

99

37

81

28 36.6

28 16.7

27 57.1

43 32

280

213

41 42

99

37

82

29 4.7

28 44.3

2$ 24.3

42 48

280

213

41 25

99

37

83

29 33.0

29 12.1

28 51.6

42

280

213

41 5

99

37

84

30 1.4

29 40.1

29 19.2

•

41 9

280

213

40 42

99

87

85

30 30.0

30 8.3

29 46.9

10 40 15

280

214

11 40 17

99

37

86

30 58.8

30 36.6

30 14.7

39 18

280

214

39 50

99

37

87

31 27.8

31 5.0

30 42.6

38 18

280

214

39 19

99

38

88

31 56.8

31 33.6

31 10.8

37 15

280

214

38 46

99

38

89

32 25.9

32 2.3

31 39.1

36 8

280

215

38 10

•

99

38

90

32 55.1

32 31.1

32 7.5

10 34 59

280

215

11 37 32

99

38

91

33 24.3

32 59.9

32 35.9

33 47

280

215

36 51

99

38

92

33 53.6

33 28.8

33 4.3

32 31

280

216

36 7

99

38

93

34 22.9

33 57.6

33 32.7

31 13

280

216

35 21

99

39

94

34 52.2

34 26.5

34 1.2

29 52

279

216

34 32

99

. 39

95

35 21.4

34 55.4

34 29.7

10 28 27

279

217

11 33 40

99

39

96

35 50.6

35 24.2

34 58.1

27

279

217

32 46

99

39

97

36 19.7

35 52.9

35 26.4

25 30

279

218

31 49

99

40

98

36 48.7

36 21.5

35 54.6

23 58

279

218

30 49

99

40

99

37 17.6

36 50.0

36 22.8

22 23

279

219

29 47

99

40

100

37 46.3

37 18.4

36 50.8

10 20 45

279

219

11 28 43

99

40

101

38 14.7

37 46.5

37 18.6

19 6

279

220

27 36

99

41

102

38 42.9

38 14.4

37 46.2

17 24

279

220

26 27

99

41

103

39 10.9

38 42.1

38 13.«

15 40

279

221

25 16

99

41

104

39 38.6

39 9.5

38 40.T

13 53

279

222

24 2

99

42

105

40 6.0

39 36.6

39 7.5

10 12 5

279

222

11 22 46

99

42

106

40 33.0

40 3.4

39 34.1

10 15

278

223

21 29

99

42

107

40 59.7

40 29.9

40 0.4

8 24

278

224

20 9

99

43

108

41 26.0

40 56.0

40 26.3

6 30

278

225

18 47

99

43

109

41 51.8

41 21.6

40 51.7

4 36

278

226

17 24

9S

44

110

42 17.2

41 46.9

41 16.8

10 2 41

278

227

11 15 59

98

44

111

42 42.2

42 11.7

41 41.4

10 44

278

228

14 32

98

45

112

43 6.7

42 36.1

42 5.7

9 58 47

278

229

13 4

98

45

113

43 30.7

43 0.0

42 29.5

56 49

277

230

11 35

98

46

114

43 54.2

43 23.4

42 52.8

54 50

277

231

10 4

98

46

115

44 17.2

43 46.3

43 15.6

9 52 51

277

232

11 8 32

98

47

116

44 39.6

44 8.6

43 37.9

50 52

277

233

658

98

47

117

45 1.4

44 30.4

43 59.6

48 52

277

235

5 24

98

48

118

45 22.7

44 51.6

44 20.7

46 53

276

236

3 49

97

48

119

45 43.4

45 12.3

44 41.3

44 53

276

238

2 12

97

49

120

46 3.5

45 32.4

45 1.4

9 42 53

276

239

11 36

97

50

121

, 46 23.0

45 51.8

45 20.8

40 54

276

241

10 58 58

97

51

122

46 41.9

46 10.7

45 39.7

38 55

276

242

57 19

97

51

123

47 0.2

46 29.0

45 58.0

36 56

275

244

55 40

96

52

124

47 17.9

46 46.7

46 15.7

34 59

275

246

54 1

96

53

125

47 34.8

47 3.8

46 32.9

9 33 1

275

248

10 52 21

96

54

TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918. 27

TABLE IX.

PATH OP TOTAL PHASE IN THE UNITED STATES.

Data for Points

on Central Line.

Longitude

Wftfit fnwn

Third Contact.

Fourth Contact.

Sun's
Altitude
a^Mid-
^^tality.

Distance

toEdceof

Path.

Greenwich.

Qreenwidi

Angle
East

Angle
East

Qreenwidi

An^
East

Angle
East

Duration.

HeanTime.

tnox N.

from

HeanTime.

fromN.

from

Point.

Vertex.

Point.

Vertex.

•

h m 8

a

•

h m s

•

•

8

•

Miles.

80

1142 46

279

217

• • • • • •

49.0

5.6

19.6

81

42 32

279

217

• • • • • •

50.4

6.6

20.0

82

42 16

279

217

• • • • • •

51.8

7.7

20.4

83

41 58

279

217

• • ■ • **. *

53.3

8.7

20.8

84

4137

279

217

• • • • • •

54.7

9.8

21.2

85

11 41 14

279

217

12 35 44

99

42

56.3

10.8

21.7

86

40 47

279

218

35 41

99

42

57.8

11.9

22.1

87

40 18

279

218

35 35

99

42

59.3

13.0

22.5

88

39 47

279

218

35 27

99

42

60.8

14.0

22.9

89

39 13

279

218

35 17

99

42

62.5

15.1

23.3

90

11 38 36

279

218

12 35 4

99

42

64.2

16.2

23.7

91

37 57

279

218

34 50

99

42

65.8

17.3

24.1

92

37 15

279

218

34 33

99

42

67.4

18.4

24.5

93

36 30

279

219

34 13

99

42

69.1

19.4

24.9

94

35 42

279

219

33 52

99

42

70.8

20.5

25.3

95

11 34 52

279

219

12 33 28

99

43

72.4

21.6

26.7

96

34

279

219

33 2

99

43

74.0

22.7

26.1

97

33 5

279

220

32 34

99

43

75.7

23.8

26.4

98

32 7

279

220

32 3

99

43

77.6

24.8

26.8

99

31 7

279

220

31 30

99

43

79.5

25.9

27.1

100

11 30 4

279

221

12 30 56

99

43

81.2

27.0

27.4

101

28 59

279

221

30 19

99

43

83.0

28.1

27.8

102

27 52

279

221

29 40

99

44

84.8

29.1

28.1

103

26 42

279

222

28 58

99

44

86.6

30.2

28.4

104

25 31

279

222

28 15

99

44

88.4

31.2

28.7

105

11 24 17

279

222

12 27 30

99

44

90.2

32.3

29.0

106

23 1

279

223

26 42

99

44

92.0

33.3

29.3

107

21 43

279

223

25 53

99

45

93.8

34.4

29.6

108

20 23

279

223

25 2

99

45

95.8

35.4

29.8

109

19 2

278

224

24 10

99

45

97.6

36.4

30.1

110

11 17 38

278

224

12 23 15

98

45

99.4

37.4

30.3

HI

16 14

278

225

22 19

98

45

101.2

38.4

30.6

112

14 47

278

225

21 22

98

46

103.0

39.4

30.8

113

13 19

278

226

20 23

98

46

104.6

40.4

31.0

114

11 50

278

226

19 22

98

46

106.3

41.3

31.2

115

11 10 20

278

227

12 18 20

98

46

108.0

42.2

31.4

116

848

278

227

17 17

98

47

109.7

43.2

31.6

117

7 15

278

228

16 12

98

47

111.2

44.1

81.8

118

6 42

277

228

15 ft

98

47

112.9

45.0

32.0

119

4 7

277

229

13 59

98

48

114.5

45.8

32.2

120

11 2 32

277

230

12 12 51

98

48

116.0

46.7

32.4

121

11 55

277

230

11 42

98

48

117.5

47.6

32.5

122

10 59 18

277

231

10 32

97

48

119.0

48.4

32.7

123

57 41

276

232

9 21

97

49

120.5

49.2

32.8

124

56 3

276

233

8 8

97

49

121.9

50.0

32.9

125

10 54 24

276

234

12 6 55

97

50

123.1

50.8

33.0

28 TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918.

TABLE X.

REDUCTIONS FOR POINTS IN THB PATH OF THB TOTAL PHASE, BUT NOT ON
THE CENTRAL LINE, TO BE APPLIED TO CENTRAL LINE DATA TO OBTAIN
TIMES OF CONTACTS.

For pointff iKirth of the central line the redncdonfl are negative.
For points south of the central line the reductions are positive.

(a) To obtain Greenwich Mean Time pf First Contact.

"^^^^^s^MLofLirt.

(/

2'

4'

e"

8^

lO'

12^

14^

16^

18^

20^

22'

24'

26^

28'

Lon^. ^^'"'*"*^.^,^^

s

8

8

8

•

8

8

8

8

8

8

8

8

8

8

8

80

2

5

7

9

12

14

16

19

21

23

26

28

30

33

85

3

5

8

10

13

15

18

20

23

26

28

31

33

36

90

3

5

8

11

14

16

19

22

25

27

30

33

36

38

95

3

6

9

12

14

17

20

23

26

29

32

35

37

40

100

1

3

6

9

12

15

18

21

24

27

30

33

36

38

41

105

3

6

9

12

15

18

21

24

27

30

33

36

38

41

110

3

6

8

11

14

17

20

23

25

28

31

34

37

89

115

3

5

8

10

13

15

18

21

23

26

28

31

34

86

120

2

4

7

9

11

13

15

18

20

22

24

26

29

31

125

2

3

5

7

8

10

12

14

15

17

19

20

22

24

(6) To obtain Greenwich Mean Time of Second Contact at points north of Central Line, or
of Third Contact at points south of Central Line.

^^••^N^ttofLirt.

(/

2'

4'

6'

8'

lO'

12'

14'

16'

18'

20'

22'

24'

2(>'

28'

Long. ^^''*^.,,^

•

8

8

'•

8

8

8

8

i

8

8

8

8

8

8

8

8

80

2

4

5

6

7

7

7.

• 6

3

• •

• •

• •

• •

85

2

4

6

7

.8

9

9

9

8

5

• •

• •

• •

90

2

5

7

8

10

11

12

12

12

11

8

• •

• •

95

3

5

7

9

11

12

13

14

14

14

13

10

• •

100

3

5

8

10

12

13

15

16

17

17

16

15

12

105

3

6

8

10

12

14

16

17

18

18

18

17

15

11

110

3

6

8

11

13

14

16

17

18

18

18

18

16

12

115 .

3

6

8

10

12

14

16

17

18

18

18

17

15

12

120

3

5

8

10

12

13

14

15

16

16

15

14

12

8

125

3

5

7

9

10

11

12

13

13

13

12

10

7

2

(c) To obtain Greenwich Mean Time of Second Contact at points south of Central Line, or
of Third Contact at points north of Central Line.

"^^--^^^iofLBt.

•

0'

2'

4'

6'

8'

10'

12'

14'

16'

18'

20'

22'

24'

26'

28'

Long. ^****'^.^

8

8

8

:

8

8

8

•

8

8

8

8

8

8

8

8

8

80

2

5

7

10

14

18

22

27

34

• •

• •

• •

• •

• •

85

2

5

8

11

15

19

23

28

34

41

• •

• •

• ■

• •

90

3

5

9

12

16

20

24

28

34

40

48

• •

• •

• •

95

3

6

9

13

16

21

25

30

35

40

47

55

• •

• •

100

3

6

10

13

17

22

26

31

36

42

48

55

64

• f

105

3

7

10

14

18

22

27

32

37

43

49

56

64

75

110

3

7

10

14

18

23

27

32

38

44

50

57

65

74

115

3

7

10

14

18

23

28

32

38

44

50

57

65

74

120

3

6

10

14

18

22

27

32

37

43

50

56

65

74

125

3

6

9

13

17

21

26

SO

36

42

48

55

63

73

TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918. 29

TABLE X.

REDUCTIONS FOR POINTS IN TBDE PATH OF THE TOTAL PHASE, BUT NOT ON
THE CENTRAL LINE, TO BE APPLIED TO CENTRAL LINE DATA TO OBTAIN
TIMES OF CONTACTS.

F(tf points north of the central line the redactions are n^ative.
For points south of the central line the reductions are positive.

(d) To obtain Greenwich Mean Time of Fourth Contact.

"*^^v,.,Dttr. of Lat.

(/

2^

V

6'

8'

lO'

12^

14'

16'

18'

20^

22^

24'

26'

28'

Long, ^"^'^^-v^^^

8

8

•

8

8

8

8

8

8

8

8

o

•

8

8

8

80

2

4

5

7

9

11

13

14

16

18

20

22

23

25

85

2

4

6

8

10

12

14

16

18

20

22

24

26

28

90

2

4

7

9

11

13

16

18

20

22

24

27

29

31

95

2

5

7

10

12

15

17

20

22

24

27

29

32

34

100

3

5

8

11

13

16

19

21

24

27

29

32

35

37

105

3

6

9

11

14

17

20

23

26

29

31

34

37

40

110

8

6

9

12

15

18

21

24

27

30

33

36

39

42

115

3

6

9

12

16

19

22

25

28

31

34

37

41

44

120

8

6

9

13

16

19

22

25

28

32

35

38

41

44

125

3

6

9

13

16

19

22

25

28

31

35

38

41

44

30 TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918.

TABLE XI.

REDUCTIONS FOR POINTS IN THE PATH OF THE TOTAL PHASE, BUT NOT ON
THE CENTRAL LINE, TO BE APPLIED TO CENTRAL LINE DATA TO OBTAIN
POSITION ANGLES AT SECOND AND THIRD CONTACTS .♦

For points north of the central line the redactions are negative for second contact and positive
for third contact.

For pc^ts south of the central line the reductions are positive for second contact and negative
for third contact.

'"^'v^Difl. of Lat.

-

(/

2'

4^

6'

8^

lO'

12^

14^

16^

18^

20^

22^

24^

26^

28''

Long. ^^^^^^

o

o

o

o

-

o

m

o

e

o

a

o

e

O

e

80

6

12

18

24

31

38

46

56

69

• •

• •

• •

• •

85

5

11

16

22

28

34

41

48

57

68

• •

• •

• •

90

5

10

15

20

25

30

36

42

49

57

68

• •

• •

95

4

9

13

18

23

28

33

38

44

51

58

68

• •

100

4

8

12

17

21

26

30

35

40

46

52

60

70

105

4

8

12

16

20

24

29

33

38

43

49

55

63

73

110

4

8

11

15

19

23

28

32

37

41

47

53

59

68

115

4

7

11

15

19

23

27

31

36

40

46

51

58

65

120

4

7

11

15

19

23

27

31

36

40

45

51

57

65

125

4

7

11

15

19

23

27

31

36

40

45

51

57

65

*NoTE.— The reductions for first and fourth contacts never exceed one degree.

The Duration of the Total Phase for pomts not on the central line is
given by the formula —

D-T-
where

■aA?

T- duration at nearest point of central line;

6— distance in miles from central line;

a-one-half the width of path through given point (last column, Table IX).

USE OF TABLES X AND XI.

The vertical argument is the longitude of the given place, the horizontal argument the
distance of the given place north or south of that point of the central line of which the longitude
is the same as that of the given place.

Example, — ^Find the times and position angles of the contacts for Jackson, Miss., whose
position is —

Longitude 90 11.1-90.185 west of Greenwich.
Latitude +32 20.0-16.^4 south of central line.

Table IX (Central line Data)
Table X . . . .

Greenwich Mean Time .

Table IX (Central Line Data)
Table XI, and Note
Angle from North Point

Table IX (Central Line Data)
Table XI, and Note
Angle from Vertex

Ist Contact.

adC<mtact.

3d Contact.

4th Contact

h m 8
10 34 46

h m 8
11 37 24

h m 8
11 38 29

h m 8
12 35 1

+ 23

+ 29

+ 12

+ 18

10 35 9

11 37 53

11 38 41

12 35 19

•
280

•
99

•
279

•
99

+43

-43

280

142

236

99

•
215

•
38

218

•
42

+43

-43

215

81

175

42

TOTAL ECLIPSE OF THE SUN, JUNE 8, 1918. 31

TABLE XII.

LOCAL CIRCUMSTANCES.

Beginning.

Middle.

Ending.

Place.

Greenwich

Angle
from

Angle

from

Vertex.

Greenwich

Magni-
tude.

Greenwich

Angle
from

Anglo

from

Vertex.

•

ICeanTime.

North
Point.

Mean Time.

Mean Time.

North
Point.

h m

a

•

h m

h m

o

e

Albany, N. Y

10 30

256

206

11 23

0.64

12 14

118

74

Allegheny, Pa.

10 30

263

208

11 27

0.74

12 20

113

66

Amherst, MaflH.

10 30

256

205

11 24

0.64

12 13

119

75

Ann Arbor, Mich.

10 26

263

210

11 25

0.74

12 20

113

66

Appleton, Wifl.

10 21

263

212

U'22

0.75

12 18

113

66

Atlanta, Ga. . .

10 36

274

212

11 36

0.92

12 32

103

49

Augusta, Me. . .

10 29

252

204

11 20

0.58

12 8

122

80

Austin, Tex. . .

10 34

288

220

11 40

0.87

12 39

92

30

Baton Bouge, 1j&.

10 37

283

216

1140

0.95

12 38

96

37

Berkeley, Cal.

9 49

290

240

11 10

0.79

12 22

86

27

Bismarck, N. Dak.

10 7

266

219

11 14

0.81

12 16

109

62

Boise City, Idaho

9 51

278

233

11 8

0.99

12 18

97

45

Buffalo, N. Y.

10 28

259

207

11 24

0.69

12 16

116

71

Cambridge, Mass

10 31

255

205

11 23

0.63

12 12

119

76

Carson City, Nev.

9 52

286

237

11 11

0.85

12 22

90

32

Charlefltm, W. Va.

■

10 32

266

210

11 30

0.80

12 24

110

60

Charlottesville, Va.

10 33

265

208

11 30

0.77

12 23

111

62

Cheyenne, Wyo. .

10 10

276

222

11 21

0.97

12 25

101

48

Cincinnati, Ohio . ^

^-

10 29

267

211

11 30

0.81

12 24

110

60

Cleveland, Ohio

10 28

262

209

11 26

0.74

12 20

113

6e

Columbia, Mo. . .

t

10 25

272

215

11 29

0.89

12 28

105

53

Columbia, S. C. .

10 87

272

211

11 36

0.88

12 30

105

52

Cohimbus, Ohio

10 29

265

210

11 28

0.78

12 23

111

62

Denver, Colo. . .

10 12

278

222

11 24 1

1.011

12 27

99

44

Des Moines, Iowa

10 20

269

215

11 25

0.85

12 24

107

57

Dover, Pel. . .

10 33

262

207

11 28

0.72

12 20

114

67

Evanston, 111. . .

10 24

265

212

11 25

0.78

12 22

111

63

Flagstaff, Ariz.

10 11

289

227

11 26

0.83

12 32

89

29

Geneva, N. Y. . . i

ft i

10 28

258

207

1124

0.67

12 15

117

72

Greencastle, Ind. .

• 1

10 28

268

212

11 29

0.82

12 25

109

59

Hanover, N. H. . .

10 29

254

205

11 22

0.61

12 11

120

77

Harrisburg, Pa. . .

» 1

10 31

261

207

11 27

0.72

12 19

114

68

Helena, Mont. . . .

1 «

9 54

272

229

11 8

0.92

12 15

103

55

Honolulu, Hawaii

* 4

9 1

331

61

9 45

0.09

10 30

23

203

Iowa City, Iowa . .

* <

10 22

268

214

11 25

0.83

12 23

108

59

Ithaca, N.Y. . . .

i

10 29

258

206

11 24

0.67

12 16

117

72

Jackson, Miss. . . .

«

10 35

280

215

11 38^

1.00 2

12 35

98

42

Juneau, Alaska . .

«

9 15

258

254

10 29

0.77

1140

108

79

Kansas City, Mo. . .

«

10 23

273

216

11 28

0.91

12 28

104

51

Little Bock, Ark.

«

10 30

278

216

11 35

0.99

12 33

100

45

Louisville, Ky. . .

•

10 30

269

212

11 31

0.84

12 26

108

57

Madison, Wis. . . .

•

10 22

265

212

11 24

0.78

12 20

111

63

MinneaTK>1iR, M^nn.

10 16

265

214

11 20

0.78

12 18

111

64

Montgomery, Ala.

•

10 37

277

213

11 38

0.97

12 34

101

45

Mount Hamilton, Cal.

•

9 51

290

238

11 12

0.78

12 23

86

26

1 Duration of totality 1".5.

> Duration of totality Ob.8.

32 TOTAL ECLIPSE OF THE SUN, JUNE 8, 19ia.

TABLE XII.

LOCAL CIRCUMSTANCES.

Place.

Begbming.

Qieenwjdi
Mean Time.

from

North

Point.

from
Vortaz.

ICiddle.

Oroanwidi
Mean Time.

Macni.
tuae.

Ending.

Greenwidi
lieaaTime.

Angle
from
North
Point.

from

Vertex.

Mount Wilson, Cal.
Nashville, Tenn. .
New Haven, Conn.
New Orleans, La. .
New Y<»k, N. Y.

Nome, Alaska . .
Oklahoma City, Okla.
Omaha, Nebr. . .
Orono, Me. . . .
Oxford, Miss. . .

Panama, Panama
Philadelphia, Pa.
Phoenix, Ariz.
Pierre, S. Dak. .
Portland, Oreg.

Poughkeepsie, N. Y.
Raleigh, N. C.
Richmond, Ya.
Sacramento, Cal. .
Salt Lake City, Utah

San Juan, P. R. .
Santa Fe, N. Mex.
Seattle, Wash.
Springfield, 111. .
St. Louis, Mo. . .

Syracuse, N. Y. .

Tallahassee, Fla. .
Topeka, Kans.

Tuscaloosa, Ala. .

Ukiah,Cal. . .

Urbana, 111. . .
Washington, D. C.
Williams Bay, Wis.

h m
10 3
10 32
10 31
10 38
10 32

849
10 26
10 19
10 29

10 33

11 8
10 32
10 13
10 11

938

10 31
10 36
10 34
9 50
10 1

10 52
10 17
9 37
10 26
10 27

10 28
10 40
10 22
10 35
9 46

10 26
10 33
10 23

294
273
258
233
259

246
280
271
251

277

308
261
292
269

277

258
268
265
288
280

284
285
273
269
271

258
279
274
277
288

268
263
265

233
212
206
216
206

265
218
216
203
214

226
207
228
219
243

206
209
208
239
228

213
223
243
213
. 214

206
213
216
214
242

212
208
212

h m
11 21
11 34
11 25
U 41
11 26

9 55
11 33
11 25
11 19
11 36

• • • •

11 27
11 28
11 18

10 58

11 25
11 33
11 31
11 10
11 17

• » • •

11 29

10 56

11 28
11 30

11 23
11 40
11 28
11 37
11 7

11 28
11 29
11 24

0.74
0.90
0.66
0.95
0.68

0.63
0.99
0.88
0.56
0.96

• • •

0.71
0.79
0.86
0.99

0.66
0.82
0.77
0.82
0.97

• • •

0.91
0.98
0.85
0.88

0.66
0.99
0.93
0.97
0.82

0.83
0.74
0.78

h m
12 29
12 30
12 15
12 38
12 16

11 2

12 33
12 25
12 7
12 33

....
12 18
12 33
12 20
12 11

12 15
12 26
12 23
12 22
12 24

....
12 33
12 8
12 25
12 27

12 14
12 35
12 28
12 34
12 20

12 25

12 21

12 21

84
105
117

96
116

lU
98
106
123
101

• • •

115
87

107
96

117

109

111

88

96

. . •

94

99

108

106

118

99

108

101

87

106
113
111

21
52
73
37
71

Ul
42
55
82
46

• • .
68
25
58
46

70
58
62
SO
42

» • •
85
52
67
54

73
43
50

46
30

58
65
63

o

S
1
1
1
X

1

1
1

J

JNE

8, 1918.

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8, 1918.

Chart II.

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