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THE HONG KONG GOVERNMENT GAZETTE, JUNE 1, 1928.
No. 322. *
ROYAL OBSERVATORY, HONG KONG.
Notice to Mariners.
1. In their Circular No. 403 the Marconi International Maritime Communication Company have authorized their operators to send weather reports to the Royal Observa- tory, Hong Kong, and shipmasters are earnestly requested to co-operate in the forecasting. and storm-warning work of the Observatory, by arranging for meteorological observa- tions to be made in accordance with the programme given below, and transmitted by the wireless operator without delay.
2. The accuracy and utility of the Observatory forecasts will increase in proportion to the number of ships cooperating, the accuracy of the observations, and the promptness with which they are despatched. In the interest of shipping, therefore, every master possessing a radio-telegraphic installation should send observations at the hours stated, namely, at 0300, 0600, 0900 and 2200 G.M.T., and endeavour to make the service as efficient as possible.
3. It is requested that mercurial barometers should be used whenever possible, and that owners should cooperate by supplying their ships with at least one good mercurial barometer, of the Board of Trade pattern. Very few aneroid barometers are satisfactory. Generally speaking, the index error varies considerably from time to time, and is seldom constant throughout the scale. Moreover their readings are usually affected by changes of temperature though they are supposed to be compensated in this respect. In every case the readings should be followed by the word Mercury" if a mercurial barometer is read, or "Aneroid" if an aneroid is read.
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4. In this revised circular corrected readings of the barometer are requested, in order to bring merchant ships into line with the larger ships of H.M. Navy, which are supplied with barometers having "Gold" Scales, for readily obtaining the barometric pressure at sea level, the freezing point of water, and norinal gravity.
It is very important that a few readings (at least four) of the barometer used for the wireless messages should be taken in Hong Kong and forwarded to the Observatory for comparison with the Standard.
5. It is requested that when within range of Cape d'Aguilar, (Call sign V.P.S.: Latitude 22° 12′ 39′′ N. and Longitude. 114° 15′ 19′′ E.) the Captain will arrange for observations to be made at 0300, 0600, 0900 and 2200 G.M.T. and for a message, prepared by the observer, to be handed to the operator for transmission, containing the following information :-
(a.) Ship's name,, position, and the time of observation (G.M.T.).
(b.) Barometer reading corrected for index error, and reduced to 32° F. sea
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level, and gravity at latitude 45°; adding “steady", 'rising" or
'falling".
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If an aneroid barometer is used its readings need only be corrected for
index error and reduced to sea level.
(e.) Temperature of the air.
(d.) Wind direction and force; adding “steady", "veering" or "backing". (e.) State of Sea.
4
4
8
or 10 covered;
(f.) State of weather (in plain language) "fine" meaning sky less than 1
fair to 1% covered; "cloudy" 10
10 more than covered.
covered;
overcast
8
10
Note:Paragraphs 5-9 are extracted from the Marconi Company's Circular No. 403.
* Cancelling G. N. No. 428 of 6th August, 1926.