F 10-
In the following table are given the number of times and number of hours the local signals were hoisted in each of the years 1925-1929:-
Year. Red Signals. Black Signals. Bombs. Number of times Number of hours displayed. Number of times. Number of hours displayed. Number of times fired. 1925 ΤΟ 3 10:00 1 1926 3 28 1 1 1927 128 3 57 61 1 1928 50 169 103 I 1929 58 46The figures in the above table include the number of hours that night signals, corresponding to the day signals, were hoisted.
The red signal indicates that a depression or typhoon exists which may possibly cause a gale at Hong Kong within 24 hours. The black signals indicate that a gale is expected at Hong Kong.
Three bombs fired at intervals of 10 seconds indicate that wind of typhoon force is anticipated.
VI. METEOROLOGICAL OBSERVATIONS FROM SHIPS, TREATY PORTS, &c.
Logs received. In addition to meteorological registers kept at about 40 stations in China, meteorological logs were received from 197 ships operating in the Far East. These logs, representing 10,153 days' observations have been utilised for amplifying the weather maps and verifying typhoon tracks. The corresponding figures for the year 1928 were 186 and 9425.
Comparison of Barometers.-The corrections to ships barometers are usually obtained by comparing their readings while at Hong Kong with those of the Observatory Standard. Occasionally ship captains bring their barometers to the Observatory to be compared with the Observatory Standard.
VII. MAGNETIC OBSERVATIONS.
From the beginning of 1928 Magnetic horizontal force, declination and dip have been determined at the Au Tau Station weekly, when possible. The instruments used are a magnetometer by Cook, Troughton and Simms, No. 31, and an Earth Inductor by the Cambridge Instrument Co. C65818. In the
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