VIII. TIME SERVICE.
Time Ball.-The time ball on Kowloon Signal Hill is dropped at 10h. and 16h. daily, except on Saturdays when it is dropped at 10h. and 13h. and on Sundays and Holidays when it is dropped at 10h. only (120th Meridian Time).
The ball is hoisted half mast at the 55th minute and full mast at the 57th minute. If the ball fails to drop at the correct time it is lowered at 5 minutes past the hour and the ordinary routine repeated at the following hour, if possible.
Time signals are also given at night by means of three white lamps mounted vertically on the Observatory radio mast. The lights are extinguished momentarily every second from 20h. 55m, to 21h, except at the 28th, 29th, 54th, 56th, 57th, 58th and 59th seconds, of each minute. The 21h. signals were repeated at midnight on December 31, the last signal indicating the close of the year 1929. The hours refer to Hong Kong Standard Time (8 hours East of Greenwich).
The Timeball was dropped successfully 658 times. There were two failures, on August 2nd and 4th at 10h. a.m, when it fell 12 seconds and 30 seconds early, respectively. The failures were due to electrical defects in the connections within the observatory. The ball was not raised on August 22nd at 4h. p.m. owing to a typhoon gale, and on August 24th and 25th at 4h. p.m. owing to faults in the exterior lines.
The error of the time ball due to accumulated error of the standard clock never exceeded 0s.3 throughout the year.
The probable error of the time ball in each month of the past five years is given in the following table.
Month. 1925 1926 1927 1928 1929 January, ±0.38 February, '22 ±0.13 -18 +0'14 ±0.13 +0.10 *12 *10 '10 March, *22 '11 11 *10 '10 April..... 16 13 *10 '10 *10 May, '11 '10 14 '10 ΙΟ June, "10 *10 13 *20 *10 July, *10 *10 *10 '11 *10 August,. *12 10 *12 '20 *12 September, '10 *10 *10 *11 *10 October, *12 *11 *11 *11 '10 November, *10 10 '10 *11 December,. *10 *13 13 '12 *14 Means, ±0.15 ±0.12 ±0.12 ±0.12 ±0.11- F 12
VIII. TIME SERVICE.
Time Ball.-The time ball on Kowloon Signal Hill is dropped at 10h. and 16h. daily, except on Saturdays when it is dropped at 10h. and 13h. and on Sundays and Holidays when it is dropped at 10h. only (120th Meridian Time).
The ball is hoisted half mast at the 55th minute and full mast at the 57th minute. If the ball fails to drop at the cor- rect time it is lowered at 5 minutes past the hour and the ordinary routine repeated at the following hour, if possible.
Time signals are also given at night by means of three white lamps mounted vertically on the Observatory radio mast. The lights are extinguished momentarily every second from 20h. 55m, to 21h, except at the 28th, 29th, 54th, 56th, 57th, 58th and 59th seconds, of each minute. The 21h. signals were repeated at midnight on December 31, the last signal indicating the close of the year 1929. The hours refer to Hong Kong Standard Time (8 hours East of Greenwich).
The Timeball was dropped successfully 658 times. There were two failures, on August 2nd and 4th at 10h. a.m, when it fell 12 seconds and 30 seconds early, respectively. The failures were due to electrical defects in the connections within the observatory. The ball was not raised on August 22nd at 4h. p.m. owing to a typhoon gale, and on August 24th and 25th at 4h. p.m. owing to faults in the exterior lines.
The error of the time ball due to accumulated error of the standard clock never exceeded Os.3 throughout the year.
The probable error of the time ball in each month of the past five years is given in the following table.
Probable Error of the Time Ball.
Month.
1925
1926
1927
1928
1929
January,
±0.38
February,
'22
±0.13 -18
+0'14
±0.13
+0.10
*12
*10
'10
March,
*22
'I I
11
*10
'10
April.....
16
13
*IO
'10
*10
May,
'I I
'10
14
'10
ΙΟ
June,
"IO
*10
13
*20
*10
July,
*10
*10
*10
'I I
*10
August,.
*I 2
10
*12
'20
*12
September,
'10
*10
*10
*I I
*10
October,
*Iz
*I 1
*II
*I I
'10
November,
*10
10
'10
*I I
December,.
*10
*13
13
'12
*14
Means,
±0.15 ±0.12
±0.12
±0.12
±0.11
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