352
Table VI. exhibits the number of lays on which certain meteorological phenomena were registered, and also the total number of thunder- storms noted in the neighbourhood 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-day means.
17. 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, Elliott 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.
A
The methods adopted in making the observations 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, Elliott Brothers, No. 55." The value of 2 Kusel was 3.44914 at 25° Cent. The value of P was 8.479. The mean value of the magnetic moment of the vibrating needle was 572.54. 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 +000052 (see
Observations and Researches inade in 1898," page 19.)
The tines of vibration exhibited in Table XII. are each derived from 12 observations of the time occupied by the magnet in making 100 vibrations, corrections having been applied for rate of chronometer and are 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.
The Honourable F. II. MAY, C.M.G.,
I have, &c.,
Colonial Secretary,
&C..
&c.
&c.
W. DOBERCK,
Director.