91
HONGKONG.
REPORT OF THE DIRECTOR OF THE OBSERVATORY FOR 1896.
Laid before the Legislative Council by Command of His Excellency the Governor.
No.9%
HONGKONG OBSERVATORY, 26th January, 1897.
SIR,I have the honour to submit my annual report for 1896 to His Excellency the Governor. My twelfth volume of "Observations and Researches" was published last autumn, and the thirteenth volume is now being printed. It contains investigations of the typhoons in 1896, which I have conducted in co-operation with Mr. FIGG. Thus all the typhoons that have been observed since this Observatory was started on the 1st January, 1884, have now been investigated. The same volume will contain a contribution to high level anemometry in the Tropics as the anemograms taken on top of the Peak are at present being measured. From a discussion of these measures the laws governing the winds at that altitude will for the first time be accurately ascertained, a result that cannot fail to benefit local storm-warnings. Two years' rainfall in China are also being tabulated, but this is of minor importance.
2. The thanks of the Government are due to the Inspector-General of the Imperial Maritime Customs of China for ordering meteorological observations to be made at the Treaty Ports and light- houses and transmitted to this Observatory, and to the Telegraph Companies for continuing to forward a number of them free of charge, and with precedence urgency, but many more telegraphic returns are required for the purpose of weather-forecasts and storm-warnings especially from the interior and the north of China, and I have ventured to apply to His Excellency for such further returns.
3. The staffs of the Eastern Extension Telegraph Company at Bolinao (Luzon), and at Sharp Peak (near Foochow), make observations at all times during the day, whenever required, and cable them direct to Hongkong. This enables Mr. FIGG to indicate the progress of typhoons very much better than would be possible without such information, but the Directors of the Companies have unfortunately refused to sanction their employees taking up this work at other stations.
4. During the past year reports were received every three hours, day and night, by telegraph from Gap Rock, the lighthouse about 30 miles to the south of the Colony, and also hourly from 6 a. till 8 p. daily by telephone from Victoria Peak. This is a great help for local storm-warnings. It would be still better if reports could be had at night also from the Peak, and if trained observers were located there, but as the cost would exceed a hundred dollars a month I have not suggested those improve- ments. Should, however, a further improvement in local storm-warnings be considered essential, this expense could scarcely be avoided.
5. Mr. FIGG has analysed his weather-forecasts for 1896 with the following results. The results for wind-direction, force, and weather are treated separately in the first instance. The forecast wind- direction is considered successful if the wind at Gap Rock blows the greater part of the 24 hours from a direction that does not differ more than 45° from the forecast (93% were successful). Forecast wind force: "light," is successful if the mean force registered at Gap Rock is a light breeze, or if the wind force does not reach the force of a moderate breeze; "moderate," if the mean is a moderate breeze, or if the wind force exceeds a light breeze and falls short of a strong breeze; "fresh," if the mean is a fresh breeze, or if the wind force exceeds a gentle breeze and falls short of a moderate gale ; "strong," if the mean is a strong breeze, or if the wind force exceeds a moderate breeze and falls short of a fresh gale; "gale," if it blows more than 40 miles per hour at Gap Rock (93% were successful). The "weather" is successful when "fine" is forecast if the mean amount of clouds is below 7-tenths of the whole sky, if sunshine or starlight prevails, and when it does not rain more than one hour out of the twenty-four; when "fair, cloudy," if the amount of clouds exceeds 3-tenths and it does not rain more than one hour; when "showery" if it rains at intervals and is fair at intervals; when wet, rainy" if it rains more than 4 hours (77% were successful). Counting days on which all three elements were correctly forecast as "success," those when two elements were justified and one failed as "partial success," those when one element was justified and two failed as "partial failure," and those when all elements failed as "total failure," we have :---
(C
Success 67 %, partial success 30 %, partial failure 2 %, total failure 1 %
Following the method used in meteorological offices and taking the sum of total and partial success as a measure of success, and the sum of total and partial failure as a measure of failure, we find finally that:-
97% of the weather-forecasts were successful.
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