145
Table VI exhibits the number of days on which certain meteorological phenomena were registered, and also the number of thunderstorms noted in the neigh- bourhood during the past year.
Table VII shows the frequency of clouds of different classes.
Table VIII is arranged as last year.
Table IX exhibits the monthly and annual extremes.
Table X contains five-days means.
21. The rainfall in inches recorded by the gauge placed in the Police Compound at Taipo, New Territories, was as follows:-Jan. 3.70, Feb. 0.07, Mar. 0.21, Apr. 12.29, May 10.15, June 9.97, July 7.20, Aug. 18.79, Sep. 3.26, Oct. 10.58, Nov. 1.38, Dec. 1.56, the total for the year 1907 being 106.16 inches, or about 13 per cent. above the amount re- corded at this Observatory.
22. The observations of magnetic declination and horizontal force published in Tables XI and XII were made with magnet No. 55 on Kew pattern unifilar magnetometer Elliot Brothers, No. 55. The dips were observed with dip circle Dover, No. 71. The height above mean sea level at which the magnets are suspended is 116 feet, and the position in which they are placed is 156 yards almost due Westward of the transit instrument. This is equivalent to a difference of longitude of 0. 33. The methods adopted in making the ob- servations and in determining and applying the corrections are explained in Appendix G of Observations and Researches made in 1885 "On the verification of unifilar magnetometer Elliot Brothers No. 55." The value of 2K used was 3.44914 at 25° Cent. The value of P was 7.037. The mean value of the magnetic moment of the vibrating needle was 570-65. From comparisons made between magnetometers No. 55 and No. 83 in the year 1898 it was shown that the correction to the horizontal force obtained by the former as given in Tables XII and XIII was +0.00052 (see "Observations and Researches made in 1898'
page 19).
The times of vibration exhibited in Table XII are each derived from 12 observa- tions of the time occupied by the magnet in making 100 vibrations, corrections having been applied for rate of chronometer and arc of vibration.
The observations of horizontal force given in Table XIII are expressed in C.G.S. units. The vertical and total forces have been computed by aid of the observed dips.
23. The Director, Dr. W. DOBERCK, went on leave at the end of May and retired on pension in September after 24 years service. I was appointed to fill the vacancy so caused, and consequent on these changes Mr. C. W. JEFFRIES, formerly at the Royal Observatory, Cape of Good Hope, was appointed First Assistant and arrived in the Colony in October last.
Hongkong Observatory,
7th March, 1908.
F. G. FIGG, Director.