E 10
VI.--MAGNETIC OBSERVATIONS.
Absolute determinations of magnetic horizontal force, dip, and declination were made near the middle of each month with instruments of the Kew pattern. In the determinations of horizontal force two sets of deflection observations were made, one before and one after the vibration observations. Four dip needles were used in rotation, two on one day of each month.
The Kew Magnetometer No. 83 was sent to England to be altered in February, but had not been returned by the end of the year.
The azimuth of the north magnetic mark was re-determined in the months of February and March, with a 5-inch micrometer theodolite loaned by the Public Works Department. The results of each night's observations were as follows:-
Date. Azimuth. February 23rd, 24th, 1st, March + 10° 17′ 43′′ E of North 10 17 34 10 17 26 Mean, 10 17 34No alteration has been made in the adopted value, which has been 10° 17' 30" since the year 1884.
The mean values of the magnetic elements for the years 1913 and 1914 were as follows:-
Declination (west) Dip (north) Horizontal Force (C.G.S. unit) Vertical Force (C.G.S. unit) Total Force (C.G.S. unit) 1913. 0° 6' 13" .30 53 41 0.37172 0.22242 0.43318 1914. 0° 8' 31" 30 53 28 0.37192 0.22351 0.43340VII.--TIME SERVICE.
A detailed description of the time service installation, together with a discussion of the rates of the electric transmitter under varying conditions of friction and impulse, was published as an appendix to the Hongkong Observations, 1913.
Time-Ball.-The Time-Ball on Blackhead Hill is dropped daily at 1pm Hongkong Standard Time (5am of Greenwich Time). The ball is also dropped at any other hour in case of necessity. No application for a supplementary time signal was made in the year 1914. The ball was dropped successfully 362 times. There were two failures, on March 17 and December 17, owing to inadvertent disconnections during alterations.
E 10
VI.--MAGNETIC OBSERVATIONS.
Absolute determinations of magnetic horizontal force, dip, and declination were made near the middle of each month with instru- ments of the Kew pattern. In the determinations of horizontal force two sets of deflection observations were made, one before and one after the vibration observations. Four dip needles were used in rotation, two on one day of each month.
The Kew Magnetometer No. 83 was sent to England to be altered in February, but had not been returned by the end of the year.
The azimuth of the north magnetic mark was re-determined in the months of February and March, with a 5-inch micrometer theo- dolite loaned by the Public Works Department. The results of each night's observations were as follows:-
Date.
February 23rd, 24th, 1st,
March
Azimuth.
+
10° 17′ 43′′ E of North 10 17 34
10
17 26
Mean,
10
17 34
No alteration has been made in the adopted value, which has been 10° 17' 30" since the year 1884.
The mean values of the magnetic elements for the years 1913 and 1914 were as follows:-
Declination (west)
Dip (north)
Horizontal Force (C.G.S. unit)
Vertical Force (C.G.S. unit)
Total Force (C.G.S. unit)
1913.
1914.
0° 6' 13"
0° 8' 31"
.30 53 41
30 53 28
0.37172
0:37192
0*22242
0·22351
0.43318
0.43340
VII-TIME SERVICE.
A detailed description of the time service installation, together with a discussion of the rates of the electric transmitter under vary- ing conditions of friction and impulse, was published as an appendix to the Hongkong Observations, 1913.
Time-Ball.-The Time-Ball on Blackhead Hill is dropped daily at 13" Hongkong Standard Time (51 a.m. of Greenwich Time). The ball is also dropped at any other hour in case of necessity. No application for a supplementary time signal was made in the year 1914. The ball was dropped successfully 362 times. There were two failures, on March 17 and December 17, owing to inadvertent disconnections during alterations.
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