1
266
Table X. exhibits the monthly and annual extremes. The extremes given for humidity and vapour tension can be regarded as only approximate as the hourly values are not calculated.
Table XI. contains the five-day means.
25. The following table exhibits the differences between the monthly mean components (exactly computed) and direction of the wind given in Table VIII. of the monthly reports and those computed by the methods used in the five years 1884-1888, and explained in previous reports; the exact values minus the approximate values :--
January,
February,
1889.
March,
April,
May,
June,
July,
August,
September,
October,
November,
December,
Mean,..
N.
E.
S.
W.
+N-S
+ E-W
Direction | (0°— 359°).
+1.01
+0.35
+0.30
+0.03
+0.82
+0.32
+0.99
.4°
+0.20
+0.40
+0.03
+0.69
+0.17
+1.37
+0.16
+0.22
0.00
+1.05
+0.05
+1.36
+0.11
+0.42
+0.02
+0.94
+0.80
+0.09
+0.21
+0.39
+0.07
+0.40
+0.24
+0.08
+0.28
+0.45
+0.18
-0.36
+0.10
+0.15
-10
+0.20
+0.47
+0.24.
-0.31
+0.32
++0.05
0°
+0.18
+0.46
+0.06
-0.04
+0.80
+0.11
+0.35
+0.34
+0.01
+0.46
+0.71
+0.34
+0.35
+0.28
+0.08
+0.43
+0.75
+0.27
+1
+10 -2°
+0.60
+0.18
-0.03
+0.47
+0.67
+0.63
+0.60
+0.39.
+0.02
+0.28
+0.58
+0.75
+0.30
+0.36
+0.06
+0.40
+0.25
-20
26. Magnetic Observations made during the year 1889:—
The observations of Declination and Horizontal Force were made with the Unifilar Magnetometer, Elliott Brothers, No. 55, and the Dips were observed with Dip Circle Dover, No. 71.
The methods adopted in making the observations and in determining and applying the corrections are explained in Appendix G. of Obs. and Res, made in 1885: "On the verification of the Unifilar Magnetometer, Elliott Brothers, No. 55." The value of log. II2 K. was 3.44944 at 20° Cent., and the value of I was + 7.596. The mean value of the magnetic moment of the vibrating needle was 0.47487 in British Units and 619.97 in C.G.S. Units.
The times of vibration exhibited in the table are each derived from 12 observations of the time occupied by the magnet in making 100 vibrations, corrections having been applied for rate of chrono- meter and are of vibration.
The observations of horizontal force arc expressed in C. G. S. Units (one centimeter, one gramme, one second), but the inonthly synopsis exhibits X, the horizontal as well as Y, the vertical, and the total forces, which have been computed by aid of the observed dips, and their values are also given in British Units (one foot, one grain, one second), and in Gauss's Units (one millimeter, one milligram, one second).
27. Dr. C. Schrader explains in his report on the magnetic survey of German New Guinea that the constants of his magnetometer were determined from comparisons made at the observatories in Hongkong, Washington and Wilhelmshafen. The comparisons made in Batavia did not agree as far as the horizontal intensity was concerned.
I have the honour to be,
The Honourable W. M. DEANE,
Acting Colonial Secretary,
&C.,
&c.,
&c.
Sir,
Your most obedient Servant,
W. DOBERCK,
Director.
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