7
503
Table VI. exhibits the amount of rain (or dew) in inches registered from half an hour before to half an hour after the hour named. It exhibits also the estimated duration of rain.
Table VII. exhibits the velocity of the wind in miles and its direction in points (1-32). The velocity is measured from half an hour before to half an hour after the hour named, but the direction is read off at the hour.
Table VIII. exhibits the amount (0-10), name (Howard's classification) and direction whence coming of the clouds. Where the names of upper and lower clouds are given, but only one direction this refers to the lower clouds. With regard to the names of clouds nimbus (nim) is only entered when the rain is seen to fall; when no rain is seen to fall cumulo-nimbus (cum-nim) is entered, and this name is also used to indicate clouds intermediate between cumulus and nimbus. Cumulo-stratus (cum-str) is the well known thunder cloud, and strato-cumulus (str-cum) signifies a cloud inter- mediate between stratus and cumulus.
Table IX. exhibits for every hour in the day the mean velocity of the wind reduced to 4 as well as 2 directions, according to strictly accurate formule, and also the mean direction of the wind.
Below this is printed a list of the phenomena observed.
16. The following annual Weather Report for 1893 is arranged as follows:-
Table VI. exhibits the mean values for the year (or hourly excess above this) obtained from the monthly reports. The total duration of rain was 600 hours. There fell at least 0.01 inch of rain on
124 days.
Table VII. exhibits the number of hours during a portion of which at least 0.005 inch of rain (or dew) was registered.
Table VIII. exhibits the number of days with wind from eight different points of the compass. The figures are obtained from the mean daily directions in Table VII. of the monthly reports. Days, with wind from a point equi-distant from two directions given, are counted half to one of these and half to the other, e.g., half of the days when the wind was NNE are counted as N, and the other half as NE.
Table IX. exhibits the number of days on which certain meteorological phenomena were registered, and also the total number of thunderstorms noted in the neighbourhood during the past year.
Table X. shows the frequency of clouds of different classes.
Table XI. is arranged as last year.
Table XII. exhibits the monthly and annual extremes. The extremes of humidity and tension are only approximate as the hourly values are not calculated.
Table XIII. contains five-day means.
Table XIV., XV., XVI. contain magnetic observations.
vapour
17. Observations of magnetic declination and horizontal force were made by Mr. PLUMMER and reduced by Mr. FIGG with the unifilar magnetometer Elliott Brothers, No. 55, and the dips were observed with dip-circle, Dover No. 71.
The
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 the unifilar magnetometer Elliot Brothers No. 55." The value of log K was 3.44930 at 26°. value of P was +7.69. The mean value of the magnetic moment of the vibrating needle was 0.45175 in English units and 589.80 in C.G.S. units.
The times of vibration exhibited in the table are each derived from 12 observations of the time occupied by the magnet in making 100 vibrations, corrections having been applied for rate of chrono- meter and arc of vibration.
The observations of horizontal force are expressed in C.G.S. units (one centimeter, one gramme, one second), but the monthly synopsis exhibits X, the horizontal, as well as Y, the vertical, and total forces, which have been computed by aid of the observed dips, and their values are also given in English units (one foot, one grain, one second) and in Gauss's units (one millimeter, one milligram, one second).
I have the honour to be,
Sir,
Your most obedient Servant,
The Honourable
THE COLONIAL SECRETARY,
&c.,
&c.,
&c.
W. DOBERCK,
Director,