F 15
The times are approximate and refer to Hongkong Standard Time (8 hours East of Greenwich).
Arrangements have been made for the hourly observation at the Cape d'Aguilar Radio Station of the intensity and type of atmospherics also the wave on which they reach a maximum. It is hoped that these observations will be of service to the Radio Research Board, and will determine whether systematic observation of atmospherics can be utilised for weather forecasting.
Upper Air Research.-2 theodolites, slide rules, hydrogen and pilot balloons for upper air research were received in May, and 19 ascents made between June 10 and September 21. The longest flight was 70 minutes on July 11. The results of the observations have been communicated to the International Commission for the investigation of the upper air.
The military Authorities have been approached with a view to obtaining the assistance of two N.C.O.s from the Corps of Royal Engineers, in order that the balloons may be observed simultaneously with two theodolites, one at the Observatory and one on the Signal Hill, Kowloon. Observation with only one theodolite necessitates the assumption that the rate of ascent can be computed from the weight and free lift of the balloon, and that it remains constant; whereas simultaneous observations with two theodolites, one at each end of a base line, furnish data for the computation of the height of the balloon at each observation.
It was thought advisable to ascertain how far the assumptions necessitated by the one theodolite method are justified in Hongkong before continuing the ascents. The rate of ascent is of course affected by vertical currents, and accumulation of data by the two theodolite method may show that in certain types of weather the single theodolite method will suffice and that in certain other types the single theodolite method should not be used.
Up to the present only two balloons have been found defective. This is gratifying as it was feared they might suffer from the voyage and climate.
The Winds of Hongkong.-A memoir on the winds of Hongkong was completed during the year and will be published shortly.
Visit to Other Observatories.—In the Spring the Director visited the Observatories at Shanghai, Kobe, Tokio and Manila to discuss with the directors the following questions:-
(1.) The substitution of Hankow observations for those at Gutzlaff in the Shanghai daily weather telegrams, and of a more westerly station than Nemuro in the list of Japanese reporting stations. Also the possibility of sending the Loochoos observations via Formosa instead of via Tokio.