- F 13
Photographic registration of declination, horizontal force and vertical force was commenced at Au Tau on January 31. The declination registers have been generally satisfactory, but the horizontal and vertical force traces are subject to derangements due to causes at present obscure. The range of temperature in the magnetograph house is too great. Superior insulation and thermostatic control of the inner chamber are desirable.
The assistance of the Officer-in-Charge of the Au Tau Police Station was kindly granted by the Captain Superintendent of Police for changing sheets, battery charging etc., but owing to Police staff changes and illness this plan was abandoned on July 1, when a Chinese attendant was engaged for the work and given quarters in the Police Station. It has been difficult to impress upon the attendant the necessity for extreme care in handling photographic paper, and honesty and promptitude in reporting. In consequence much register has been lost, and although some improvement has been recently effected, the present arrangements are unsatisfactory. It will ultimately be necessary to adopt others of a more elaborate nature, if reliable results are to be obtained.
defects.
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 20th 55m. to 21h., except at the 28th, 29th, 54th, 55th, 56th, 57th, 58th and 59th seconds, of each minute. During the alterations to the time ball tower (referred to in next paragraph) brighter lights were used for the lamp signals, and the programme was repeated at 10h. and 16h. in the hope that the signals would be observed from ships in the harbour by means of telescopes or binoculars. They were observed by certain ships to the S.E. of the Signal Hill but were not visible from the Harbour Office. The 21h. signals were repeated at midnight on December 31, the last signal indicating the close of the year 1928. The hours refer to Hong Kong Standard Time (8 hours East of Greenwich).
The time ball was dropped 365 times without failure. From April 29 to October 11 the apparatus was not in use, owing to alterations to the tower.
The error of the time ball due to accumulated error of the standard clock never exceeded 0s.3 throughout the year.
- F 13
Photographic registration of declination, horizontal force and vertical force was commenced at Au Tau on January 31. The declination registers have been generally satisfactory, but the horizontal and vertical force traces are subject to derangements due to causes at present obscure. The range of temperature in the magnetograph house is too great. Superior insulation and thermostatic control of the inner chamber are desirable.
The assistance of the Officer-in-Charge of the Au Tau Police Station was kindly granted by the Captain Superintendent of Police for changing sheets, battery charging etc., but owing to Police staff changes and illness this plan was abandoned on July 1, when a Chinese attendant was engaged for the work and given quarters in the Police Station It has been difficult to impress upon the attendant the necessity for extreme care in handling photographic paper, and honesty and promptitude in reporting In consequence much register has been lost, and although some improvement has been recently effected the pre- sent arrangements are unsatisfactory. It will ultimately be necessary to adopt others of a more elaborate nature, if reliable results are to be obtained.
defects.
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 20th 55m. to 21h., except at the 28th, 29th, 54th, 55th, 56th, 57th, 58th and 59th seconds, of each minute. During the alterations to the time ball tower (referred to in next paragraph) brighter lights were used for the lamp signals, and the programme was repeated at 10h. and 16h. in the hope that the signals would be observed from ships in the harbour by means of telescopes or binoculars. They were observed by certain ships to the S.E. of the Signal Hill but were not visible from the Harbour Office. The 21h. signals were repeated at midnight on December 31 the last signal indicating the close of the year 1928. The hours refer to Hong Kong Standard Time (8 hours East of Greenwich).
The time ball was dropped 365 times without failure. From April 29 to October 11 the apparatus was not in use, owing to alterations to the tower.
The error of the time ball due to accumulated error of the standard clock never exceeded Os.3 throughout the year.
No comments yet.
Private notes are available after approval.