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# VIII. TIME SERVICE
Time Ball.-The Time Ball on the Signal Hill, Kowloon, is dropped daily at 13. Hongkong Standard Time (5 a.m. of Greenwich Time). The ball is also dropped at any other hour in case of necessity. One application for a supplementary time signal was made in the year 1917.
The ball was dropped successfully 347 times. There were three failures:-On January 28th the trigger was found to be displaced and it was impossible to place the ball upon it before 13. On April 15 the ball dropped at about 30 seconds before 13", owing to an electrical defect. On October 13 the ball failed for no ascertainable cause. There was no fault at 14 when the ball fell correctly.
The apparatus was under repair from June 16-29.
The ball fell with an error of 0.3, or less, on 327 occasions, and with an error of 0.4 or 0.5 on 11 occasions. Errors of 0.6 occurred three times, 0.9 twice, and 0.7, 0.8, 1.7, and 1.3 once each.
The probable error of the Time Ball was 0.1 less than in 1916, which was the best year on record up to that date. The monthly values for the past 5 years are given below:--
# Probable Error of Time Ball
Month 1913 1914 1915 1916 1917 January, +0.20 +0.18 ±0.17 +0.15 ±0.17 February, ... ... ... ... ... March, '54 '21 '17 '17 '1 April, '21 '22 '38 '18 ... May, '11 '25 '16 '10 '1; June. '10 '16 '15 '17 '10 July... '17 '20 '17 '10 '21 August, '15 '15 '10 '1 ... September, '10 '14 '13 '11 '10 October, '12 '14 '10 '13 '10 November, '17 '13 '16 '13 '10 December. '26 '28 '14 '11 '10 Means, +0.20 ±0.19 ±0.19 ±0.14 '13Transit Instrument.~ Observations for time were made daily with the 3-inch transit instrument and the Hipp tape chronograph by the Chinese computers, weather permitting.
The number of observations in the years 1916 and 1917 were as follows:--
1916 1917 Transits, 1,778 1,924 Level determination, ..... 290 952 Azimuth 34 14 Collimation 40 ...F 10
VIII. TIME SERVICE.
Time Ball.-The Time Ball on the Signal Hill, Kowloon, is dropped daily at 13. Hongkong Standard Time (5 a.m. of Green- wich Time). The ball is also dropped at any other hour in case of necessity. One application for a supplementary time signal was made in the year 1917.
The ball was dropped successfully 347 times. There were three failures:-On January 28th the trigger was found to be dis- placed and it was impossible to place the ball upon it before 13. On April 15 the ball dropped at about 30 seconds before 13", owing to an electrical defect. On October 13 the ball failed for no ascertainable cause. There was no fault at 14 when the ball fell correctly.
The apparatus was under repair from June 16-29.
The hall tell with an error of 03, or less, on 327 occasions, and with an error of 04 or 05 on 11 occasions. Errors of 06 occurred three times, 09 twice, and 07. 08. 17·0, and 13 once each.
The probable error of the Time Ball was (01 less than in 1916, which was the best year on record up to that date. The monthly values for the past 5 years are given below:--
Probable Error of Time Ball.
Month.
1913
1914
1915
1916
1917
January,
+0.20
+0.18
±0.17
+0'15
±0.17
February,
44
*28
"10
March,
'54
'21
17
17
[1
April,
*21
22
*38
18
May,
II
'25
16
*10
*! ;
June.
'10
16
15
17
*10
July...
17
'20
∙17
*10
21
August,
15
15
*10
*I [
September,
10
14
13
* 1 1
'10
October,
'12
*14
*10
*13
*10
November,
17
13
16
13
10
December.
*26
*28
14
"I I
*10
Means,
+0:20 ±0.19
±0.19
±0.14
2013
Transit Instrument.~ Observations for time were made daily with the 3-inch transit instrument and the Hipp tape chronograph by the Chinese computers, weather permitting.
The number of observations in the years 1916 and 1917 were as follows:--
Transits,
Level determination, .....
Azimuth
Collimation
1916
1917.
1,778
1.924
290
952
34
14
40
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