q 7H
8.8 H
.3 a \
7 1 **
J3 S [Amount
- 5/i
-5/o
- 2/8
- 2/2
- 1/8
- 1/2
- 1/2
- 1/9
- 2/6
- 2/8
- 2/8
- 3/6
Total observed
range
8/9
7/7
5/9
4/7
, /g
2 f \
2/O
, /,
6/3
4/2
5/4
8/4
Calculated range. .
8/2
5/9
3/8
2/9
2/5
2/5
2/9
3/4
3/4
3/8
7/i
Summer range, S. .
13/5
IO/I
7/7
6/6
5/2
4/o
4/3
4/3
8/8
6/3
7/0
/3
Winter range, W. .
5/2
5/8
4/6
3/6
2/2
0/9
2/4
2/9
4/3
3/8
5/8
5/6
Ratio
2.60
1.74
1.67
i 8t
2 16
4-44
I 7Q
I 48
2.O5
1.66
1. 21
2. 02
W"
* / 1
i /
'
* J v
* 17
* .if"-*
i O 1
II. 2 H
lo.oH
10.6 H
10.8 H
10.9 H
10.0 H
(7. i H)
21. 6 H)
21. 2 H)
(6.9 H)
19.0 H)
19.6 H)
J-sJjn....
20.0 H
(17.8 H)
19. i H)
19.7 H)
(16.9 H)
15-3 H)
10.8 H
12.4 H
ii. 3 H
12.6 H
12.1 H
n.4H
302
SCIENTIFIC RESULTS OF ZIEGLER POLAR EXPEDITION
An inspection of the mean yearly ranges in diurnal variation for the stations of the above
tabulation indicates that these ranges are in some way dependent upon the values of the respective
magnetic dips, the greater ranges being associated with the greater inclinations. Dr. Bauer *
has announced a law covering this apparent interrelation, namely, that the mean value, d, for
the year of the total diurnal amplitude of the magnetic declination is a function of the mag-
netic latitude, ?', which may be in the general case expressed mathematically as
d = k secV,
in which the value of ?' is derived from the magnetic inclination, /, in accordance with the
well-known formula
tan ^' = 0.5 tan I ;
k is a constant depending upon the position of the particular series under discussion in the
sun-spot cycle. Dr. Bauer's preliminary value of k is 2/58. Pending greater elaboration by
him it has seemed desirable in connection with above compilation to determine values of k by
grouping these stations in order of the approximate sun-spot frequencies given on page 297.
Accordingly values have been derived by the method of least squares from groupings of
stations as indicated in the following summary of results :
Grouping stations number
Mean sun-spot
frequency for
grouping
Resulting
value of k
81
/
2.71
i, 2, 4 to ii, 13, 15, 17, 22, and 24. .
12 16 18 19 20 23 and 25
60
M
2.52
2.^6
The ranges for the individual stations of the groupings have been calculated using the
above values of k and the results placed against the actually observed quantities for each
station. The agreement between the observed and computed ranges is, in the main, quite
satisfactory,
MAGNETIC DISTURBANCES
As already stated, those days of observation on which particularly great disturbances in
magnetic declination occurred may be readily noted by reference to the tabulation of circle
readings of the magnet for the days on which the horizontal circle was shifted (see pages 20 to 26).
In view of the fact that no continuous observations were made either for magnetic inclination
or intensity in connection with those for declination, it has not been deemed worth while to
attempt any general discussion or comparison of these disburbances. As will be noted from
the miscellaneous remarks (pages 32 to 40) , the magnetic storms were very frequently associ-
ated with the aurora borealis. On the other hand, the auroral displays were not always accom-
panied by magnetic disturbances, and vice versa.
The observations of November i, 1903, between midnight and 8 A. M., local mean time
are of particular interest, as they cover the final portion of the great magnetic storm of October
*A remarkable law, by L. A. Bauer. Journal of Terrestrial Magnetism. Volume II, p. 70. Cincinnati,
1897. Also United States magnetic declination tables and isogonic charts for 1902, by I/. A. Bauer. U. S. De-
partment of Commerce and Labor, Coast and Geodetic Survey, O. H. Tittmann, Superintendent. 2d edition,
p. 51. Washington, 1903.
MAGNETIC OBSERVATIONS
303
31 to November i, 1903.* The extreme values of declination observed at Teplitz Bay during
this period were 37 31' E at 4:01 A. M. and 20 13' E at 5:49 A. M., local mean time, the
greatest range thus being 17 18' in 1.8 hour. During the same absolute period the records
of the Cheltenham Magnetic Observatory of the United States Coast and Geodetic Survey show
an extreme range of 32 , while the maximum range for the entire storm at this point was about
three times as much, viz., 97. i. From this comparison it appears highly probable that during
the maximum violence of this disturbance on October 31, 1903, the extreme range in magnetic
declination at Teplitz Bay may have been as much as 52.
The highest value observed during the entire series was 37 31' E, as above, on November
i, 1903 ; the lowest, 19 51' at 8:27 p. M. on June 15, 1904. The absolute observed range was,
therefore, 17 40'. The unusual character and magnitude of the disturbance of October 31,
1903, is thus at once apparent.
SECULAR CHANGS IN MAGNETIC DECLINATION
The only previous observations of the declination of the magnetic needle at Teplitz Bay
available for use in determining the secular change in this element are those made by Com-
mander Cagni, of the Italian Expedition of 1899 and 1900. His observations as reported by
Professor Palazzo f have been corrected for diurnal variation as determined from the preceding
discussion. The following table gives a synopsis of these determinations so reduced (the cor-
rections on account of diurnal variation are the mean values over the respective periods of
observation) :
Date
(A
"Sv
O D
*7 (fl
^ ,Q
O
Local
mean time
Mean observed
east
declination
Correction
diurnal
variation
Mean reduced
east
declination
Resulting
mean values
1899
h m h m
/
/
/
o /
6
I A -in I *\ ^O
21 O3 Q
+ ii 6
21 15 5
21 15.6
August 30
4
IO 3Q 1 1 ^8
16.4
o 6
is. 8
1900
Tulv ii.. .
9
14 46 - i 8 38
21 14.8
+ 2 3-i
21 ^7.Q
"I
Tulv 14 .
8
16 IQ - 17 s8
OO.Q
-(-25.7
26.6
July 18...
5
ii 07 - 12 oo
16.1
4-5
ii. 6
|
21 25.0
July 19
3
14 35 - 15 09
16.6
+ 12.8
29.4
July 24
S
9 24 - ii 34
27.1
8.6
18.5
August 2
8
Q 41 - II I*
34.1
8.0
26 i
j
The resulting mean values of 21 15/6 and 21 25/0 correspond to mean of day for the
epochs 1899.66 and 1900.55 respectively.
Unfortunately the multitudinous duties of the various members of the Ziegler Expedition
field force prohibited making observations at the Italian station until just shortly prior to the
* Journal of Terrestrial Magnetism and Atmospheric Electricity, volume IX, 1904, pp. 25-33 ', also An-
nalen der Hydrographie und maritimen Meteorologie, 1904, Heft III, pp. 112-127.
t Osservazioni scientifiche esequite durante la spedizione Polare di S. A. R. Luigi Amedeo di Savoia, Duca
degli Abruzzi. Milan, 1903. Pp. 453-462. (Relazione sulle osservazioni magnetiche fatta dal Professore
Luigi Palazzo.)
304
SCIENTIFIC RESULTS OF ZIEGLER POLAR EXPEDITION
final retreat south. As a result but one set of declination observations at Commander Cagni's
station could be made. This set is herewith given in its entirety :
Station : Italian station, Teplitz Hay Date : June 23, 1904
Instrument : Magnetometer IIII Observer : W. J. P.
Mark : Magnetic observatory
Magnet : No. 4 Line of detorsion : 54
Chron.
time
Scale
Scale readings
Horizontal circle readings
Left
d
56.3
58-6
57-3
54-9
5i-5
5i-4
52-4
52.3
50-7
56.0
57-o
57-0
57-o
56.8
56.3
55-9
Right
Mean
Mark
Magnet
// m
II 00
02
04
06
10
12
14
16
18
20
22
24
28
30
32
34
E
E
E
E
I
I
I
I
I
I
I
I
E
E
E
E
d
58.9
60.3
58.9
56.9
49-9
50.0
51-2
50.8
49-4
44-2
45-3
46.0
57-9
57-9
57.3
56.9
d
57.60
59-45
58.10
55-90
50.70
50.70
51.80
51-55
50.05
50.10
5i-i5
51.5
57-45
57-35
56.80
56.40
Before
After
A
B
A
B
/
347 57-7
167 56.7
347 57-9
167 56.9
/
94 08.7
274 "7-5
94 08.2
274 07.5
Meai
is
347 57-3
94 07.98
Scale er
Scale in
A
ect, me
verted,
xis
an
d
57-38
50.94
mean
54.16
Mean scale reading, erect.
Axis
d
57.38
54.l6 !
Scale Axis
Reduction to axis
+ 3-22
+5/06
Circle reading
Q4 O7/q8
Magnetic S. M. reading. .
94 13-0
Mark reading
347 57-3
Azimuth of mark*
2 75 46.75
True S. M reading ....
72 10.6
Magnetic declination, east
Diurnal variation
22 02.4
9.1
Mean declination, east. . .
21 53-3
Mean chron. time
Chron. cor. on L. M. T. .
Local mean time.
h m
ii 17.0
ii 17.0
Remarks :
Calm and clear
Temperature : + I2.o
At end line of detorsion 57
* Counted from south around by west from o to 360.
MAGNETIC OBSERVATIONS 305
Owing to the fact that no suitable instrument was available, observations at the observatory
simultaneous with the above could not be made. The observations nearest in point of time at
the hut are those of June 22 and June 23. Correcting the two-minute readings of June 22
between 20 hours and 24 hours for diurnal variation a mean value of 22 51' results. In like
manner, the observations on June 23 between 16 hours and 20 hours give a mean value of
22 19'. It thus appears, since the average value during the period June 12 to July i is 22 32',
that, while the general magnetic conditions preceding the observations at the Italian station by
thirteen to fourteen hours were such as to give declinations high by about 19', the conditions
six to seven hours later were such as to give declinations low by about 13'. It therefore seems
quite probable that between n and 12 A. M. the magnetic conditions were about normal, and
hence a direct comparison with the preceding may be made.
As already noted, Commander Cagni's results at about the same season of year were
21 15/6 and 21 25/0 for the epochs 1899.66 and 1900.55, or in the mean 21 20/3 for 1900.10.
The result above for epoch 1904.48 is 21 53/3; hence the apparent effect in the elapsed
interval of 4.4 years due to secular variation is an increase of east declination of 33'. Assum-
ing a linear change over the interval, the secular change in magnetic declination in the region
of Teplitz Bay may be taken as about
+ 7/5 per year.
It may be noted that this value is of the same magnitude as those deduced by Dr. Solander*
for Mossel Bay and Cape Thordsen, Spitzbergen, for the periods 1873.5 to 1899.7 an d 1883.2
to 1899.7, viz., 7/3 and 7/8 decreasing west declination respectively. The geographical posi-
tions of these stations are : Mossel Bay, 79 53' north latitude and 16 04' east longitude ; Cape
Thordsen, 78 28' north latitude and 15 42' east longitude.
* Missions scientifiques pour la mesure d'un arc de meridian au Spitzberg entreprises en 1899-1902 sous
les auspices des gouvernements Su^dois et Russe Mission Suddois. Tome II Determinations magntiques faites
au Spitzberg pendent I'e'te 1899, par E. Solander. Stockholm, 1903, p. 50.
306
SCIENTIFIC RESULTS OF ZIEGLER POLAR EXPEDITION
ANNUAL VARIATION IN MAGNETIC DECLINATION
By means of the preceding value of the annual rate of secular variation in magnetic declina-
tion at Teplitz Bay the monthly mean hourly declinations and means were reduced to epoch
1904.0 as per tabulation on page 288. By the use of Bessel's periodic function in the particular
case of a cycle of twelve equidistant observations the following expression has been obtained (
after the methods detailed on page 290, as representing the annual variation :
D=22 38. '5 + 9- '27 sin (8+ 244 59') + 2. '32 sin (20+ 141 07')
+ 1/41 sin (3 + 4 45') 0/33*
In this formula the angle counts from the middle of June as o, no account being taken
of the inequality in length of months. The addition of a fourth term results in no improve-
ment, as in this case the probable error is identical with that above. It may be noted that the
range of variation on the mean of year is unusually large, the maximum deflection early in
December being + 10/2 while the opposite extreme about the middle of August is 10/0.
The computed and observed values are shown graphically to scale in figure 20. The following
summary of variations on the mean yearly value will serve further to indicate the agreement
between the observed (O) and computed (C) quantities, easterly deviations being denoted by
a plus sign, and vice versa :
Month
O
c
0-c
Month
O
C
O-C
June
f
- 4.8
/
- 6.8
/
+ 2.O
December. . . .
/
+7.6
/
+9-7
r
2.1
Tulv
IO I
86
I. 1 !
January
+8.1
+7-o
+ I.I
August
Q.Q
IO.O
+0.1
February ....
+5-3
+5-4
O.I
C A
6 8
4-1 4
March
+ i.-j
+3-9
0.6
O 7
4- i 8
2 5
April
+ 1.2
O.I
+ 1-3
4-II 7
4- Q O
+2.7
May. .
6-3
4.4
1.9
*The probable error of a single representation is 0/33.
1
a
*T
$ ll
CO JJ
P Sg
a! Sg
S a^
s|5
16
z S?
S -55
I- ca
uj a v
II!
7 in V
Hi *-
< 1 S
KJ
I |f.
^ aS
Us
"H
V
g
.2
'O
E
O
t*
' HE
UNIVERSITY
MAGNETIC OBSERVATIONS 307
INCLINATION
INSTRUMENT AND METHODS
Observations for dip were made, as already stated, with the United States Coast and Geo-
detic Survey Cassela dip circle No. 5676. For the various standardization observations before
and after the work of the Expedition see pages n and 12. The instrument was mounted in
the observing hut on pier D (figure 2) September 28, 1903. Except for observation and clean-
ing and use at the Italian magnetic station on June 6, 20, and 27, 1904, it remained undis-
turbed. On the last three occasions it was returned to its pier immediately after the comple-
tion of the observations.
During the winter the needles were turned on the agates by means of wooden pliers.
Proximity of the hand produced condensation which froze on the needles ; this appeared,
though slight, even while the blades were being rubbed with several thicknesses of tissue
paper. Ice crystals continually formed on the instrument, and the frosted roof contributed a
constant downpour of fine particles. A linen hood, conical in shape, was suspended from the
roof and covered the instrument and top of pier D when not in use. About December 22 a
paper hood was substituted with better success.
The bar magnets and four needles were kept outside of the observatory in a canvas-covered
box, which is shown on the plat as magnet box No. i. This box was secured to a post about
1.5 meter from the ground and could be used as a table or shelf on which the needles were
magnetized in good weather. During the winter, when light and weather were both unfavor-
able, the needles were magnetized in the west end of the observatory. The bar magnets were
returned immediately after the operation to magnet box No. i.
On October 5, before commencing observations, needle 3 was observed upon, while decli-
nation magnet No. 4 was reversed several times at its stowing place. Needle 3 was kept oscil-
lating in the magnetic meridian. The same operation was repeated on two subsequent occasions
during the winter. On June 7 the same observation was again made, and also with the needle
in the magnetic prime vertical. In all these observations no effect was detected on the oscil-
lating dip needle.
A small adjusting pin was kept in a vertical hole on pier D. As it was necessary to use
this pin to unloosen the stops on the horizontal circle before observing, the fact of its removal
before each day's work is not noted. During the dip observations it was placed on top of the
east window (south end). The needle not being observed upon was kept on the north end of
the east plate of the observatory.
Time was noted by watch P, which was always hung on the middle stud of the south wall
of the hut. On one occasion, November 30, chronometer Negus 1809 was used and was placed
at foot of pier M against the north side.
Observations were made after the order prescribed for use in the field operations of the
United States Coast and Geodetic Survey. This observing scheme is indicated by the follow-
ing specimen set taken at random from the Teplitz Bay series :
SCIENTIFIC RESULTS OF ZIEGLER POLAR EXPEDITION
Station : Teplitz Bay
Dip circle No. 5676
Dale : January 18, 1904
Observer : W. J. P.
Needle No. 3
End of needle marked A down
Circle east
Circle west
Circle west
Circle east
Needle face east
Needle face west
Needle face east
Needle face west
S
N
S
N
S
N
S
N
/
82 53
52
/
82 55
55
/
83 21
15
/
83 10
IO
/
83 27
23
o /
83 26
19
/
83 13
II
/
83 15
J3
82 52-5
82 55-o
83 18.0
83 10.0
83 25.0
83 22.5
83 12.0
83 14.0
82 53/75
83 o
83 14- 'o
3-88
83 23/75
83 I
83 13/0
8/38
Mean : 83 11/13
Polarities reversed : end of needle marked B down
Circle east
Circle west
Circle west
Circle east
Needle face east
Needle face west
Needle face east
Needle face west
S
N
S
N
S
N
S
N
/
83 28
35
/
83 29
35
/
83 II
03
/
83 07
03
O /
83 27
27
O /
83 23
23
/
83 03
02
o /
83 oo
GO
83 31-5
83 32.0
83 07.0
83 05.0
83 27.0
83 23.0
83 02.5
83 oo.o
83 31/75
83 j
83 06/0
8/88
83 25/0
83 i
83 01/25
3/12
Mean : 83 16/0
Resulting dip : 83 13/6
Chron. time of beginning
Chron. time of ending.
h m
14 58
15 45
Mean chronometer time
Chron. correction on L. M. T.
15 22
+ 02
Local mean time
Magnetic meridian reads.
15 24
24 19'
Circle in mag. prime vertical
o /
Circle N. Needle S end 25 24
Needle N end 25 58
Circle S. Needle N end 22 23
Needle Send 23 31
Mean.
24 19
MAGNETIC OBSERVATIONS
309
When observing with two needles the observations with first polarity of the first needle
were immediately followed by the complete determination with the second needle (polarities of
both needles being reversed at the same time), after which observations with the second polarity
of the first needle were made. By this arrangement the final means from each needle correspond
to practically the same epoch of time. As will be noted from the above specimen, two settings
were made on each end of the needle in every position except in those cases where these differed
by ten minutes or more of arc, when an additional observation was made and the mean of the
three readings taken.
RESULTS
Only the final results for each needle and their means are shown in the tabulation following,
the mean values being adopted without correction (see page 12). The time is the mean of
the times noted at beginning and end, and is expressed in local mean time, reckoned from
midnight throughout the twenty-four hours. The observer is indicated by the initials (see
page 17).
Tabular summary of observations of magnetic inclination at Teplitz Bay
Date L. M. T.
Needle 3
Needle 4
Mean
Observer
Remarks
1903
Oct. 5
h m
16 28
/
83 16.4 N
o /
83 17.3 N
/
83 i6.8N
W. J. P.
12
19
n 18
15 24
36.6
08.8
28.3
10.2
32-4
09-5
Do.
Do.
Magnetic meridian as deter-
mined October 5.
29
12 34
10.6
08.4
09.5
Do.
3
'5 27
ii. i
' 12-7
11.9
Do.
Nov. 20
17 02
13.6
08.7
II. 2
Do.
3
19 52
'5-9
10.8
13-4
Do.
Dec. 3
15 06
10.7
12.6
ii. 6
Do.
4
10 10
14.4 14.4
14.4
Do.
7
19
H 3
10 36
09.9
u-5
11.8
22.6
10.8
17.0
Do.
Do.
Corrected for observation in
magnetic azimuth i.
21
M 59
16.2
18.8
17-5
Do.
25
II 22
09.8
13-2
"5
Do.
26
8 30
13-7
12.8
13-2
Do.
1904
Jan. 5
932
"3
13.0
12.2
Do.
9
9 5
10.5
18.2
14.4
Do.
14
15
14 34
9 42
08.3
12.4
05.4
08.0
06.8
10.2
Do.
Do.
Aurora in north of large extent,
but not brilliant.
18
IS 24
13.6
13.0
13-3
Do.
19
10 01
12.4
09.6
II.
Do.
25
14 ii
12.2
13-5
12.8
Do.
26
10 02
12.6
IO.O
"3
Do.
3 io
SCIENTIFIC RESULTS OF ZIEGLER POLAR EXPEDITION
'Jabular summary of observations of magnetic inclination at Teplitz Bay Continued
Date
L. M. T.
Needle 3
Needle 4
Mean
Observer
Remarks
1904
Feb. i
h m
14 32
/
II. 2
/
17-5
o /
14.4
Do.
2
10 32
12.9
08.4
10.6
Do.
8
14 18
08.6
10.4
cg-5
Do.
15
20 IO
12.4
04.2
08.3
R. R. T.
22
16 12
10.6
08.9
09.8
W. J. P.
24
20 44*
19.6*
13.7'
16.6'
R. R. T.
29
15 04*
10.5*
07.0*
08.8-
Do.
Revolver not taken to hut.
Mar. I
10 30
09.1
10.7
09.9
Do.
Do.
18
II 06
16.7
12.2
14.4
Do.
Revolver removed.
19
16 32
II.
17.9
14-4
Do.
Do.
24
7 4'
12.2
09.4
10.8
Do.
Do.
28
15 8
83 14.8 N
83 13.2 N
83 14.0 N
R. R. T.
Do.
29
9 52
I5-I
12.6
13.8
W. J. P.
Do.
April i
10 48
16.7
14-4
15-6
R. R. T.
Do.
4
14 20
"3
10.9
n. i
W. J. P.
Do.
5
9 54
13-2
14-4
13-8
Do.
Do.
n
15 29
05-7
14.2
IO.O
Do.
Do.
12
9 58
16.3
14-7
iS-5
Do.
Do.
18
14 46
15-4
83 15-9
83 15-6
Do.
Revolver left in usual place over
night.
19
9 44
01.5
82 55-5
82 58.5
Do.
Revolver removed.
25
14 20
17.6
83 15-5
83 16.6
Do.
Do.
26
9 20
II.O
12.8
11.9
Do.
Do.
May 2
14 06
06.7
10.7
08.7
Do.
Revolver permanently removed.
3
9 16
09-5
12.8
II. 2
Do.
9
15 12
08.9
16.6
12.8
Do.
10
9 5
12.6
19.2
15-9
Do.
16
15 4
10.6
08.4
09-5
Do.
17
IO OO
13-2
I5-I
14.2
Do.
23
15 31
07-5
10.5
Og.O
Do.
24
IO 2O
n.8
14.6
13-2
Do.
3
IS 12
08.6
06.9
07.8
Do.
3i
10 00
14.4
15-0
14.7
Do.
Needles No. i and No. 2.
MAGNETIC OBSERVATIONS
1 abular summary of observations of magnetic indications at Teplitz Bay Continued
Date
L. M. T.
Needle 3
Needle 4
Mean
Observer
Remarks
1904
June 6
A >
15 24*
/
01.3*
/
03-5*
/
02.4*
Do.
See foot-note.
6
15 22
17.3
I2.O
14.6
Do.
7
10 04
13-4
14.5
14.0
Do.
'3
15 3
14.0
"5
12.8
Do.
14
9 46
15-2
14.8
15.0
Do.
20
5 3*
01.9*
04.7*
3-3*
Do.
20
15 28
09.6
I2.O
10.8
Do.
21
10 03*
II. 2*
08. I*
09.6*
Do.
21
9 53
12.0
18.0
15-0
Do.
27
16 18*
09.8*
19.4*
14.6*
Do.
27
16 18
18.2
20.4
19-3
Do.
* These observations were made at Italian station.
NOTE. When the observations of June 20 at the Italian station were being made an iron bolt was found at
the foot of the pier ; needle was not affected while it was being removed, but probably the observations of
June 6 are vitiated.
The following monthly mean values for magnetic dip result from these observations :
Epoch
No.
obs'ns
each
needle
Dip by
Resulting
mean
dip
Needle No. 3
Needle No. 4
/
/
/
1903.80
5
83 16.70 N
83 15-38 N
83 16.0 N
1903.80
4*
11.72*
12.15*
ii.sr
1903.90
2
14-75
09-75
12.3
I903-95
7
12.31
I5-I7
13-7
1904.04
8
11.66
"34
"5
1904.12
7"
12.26"
IO.O2*
u.i
1904.22
6
I3-I5
12.67
12.9
1904.28
9
12.08
12.03
12. 1
1904.37
10
10.48
12.98
II.7
1904.46
7
14.24
14.74
M-5
Omitting October 12, 1903. b Including two values, needles No. I and No. 2.