Report of the Kew Observatory Committee, 



3 



8.30 p.m. respectively, the range amounting to [0*0050 C.G.S. unit 

 (or about 1/37 of the whole component). Between 7.30 and 8.30 

 p.m., this element fell 0*0036 C.G.S. unit. The vertical force 

 reached its maximum about 6 p.m., and its minimum about 8.30 p.m., 

 but as the trace unfortunately got off the sheet near the minimum, 

 it can only be said that the range of vertical force exceeded 0*0036 

 C.G.S. unit. 



Both storms were presumably associated with the aurora simul- 

 taneously seen in the British Isles. The March storm was the 

 largest recorded since August, 1894. 



The hourly means and diurnal inequalities of the magnetic elements 

 for 1898, for the quiet days selected by the Astronomer "Royal, will 

 be found in Appendix I. 



A correction has been applied for the diurnal variation of tempera- 

 ture, use being made of the records from a Richard thermograph as 

 well as of the eye observations of a thermometer placed under the 

 Vertical Force shade. 



The mean values ut the noons preceding and succeeding the selected 

 quiet days are also given, but these of course are not employed in 

 calculating the daily means or inequalities. 



The following are the mean results for the entire year : — 



Mean Westerly Declination * 17° l'*4. 



Mean Horizontal Force 0*18364 C.G.S. unit. 



Mean Inclination 67° 17'*6. 



Mean Vertical Force 0*43885 C.G.S. unit. 



Observations of Absolute Declination, Horizontal Intensity, and 

 Inclination have been made weekly, as a rule. 



A table of recent values of the magnetic elements at the Observa- 

 tories whose publications are received at Kew will be found in 

 Appendix Ia to the present report. 



In September Professor Luigi Palazzo of the Ufficio Centrale 

 di Meteorologia, Rome, paid a visit to the Observatory for the 

 purpose of comparing the Kew magnetic instruments and his own. 



Dr. van Rijckevorsel also spent some time in the summer in 

 making a further comparison between his magnetic instruments and 

 those at Kew. 



Mr. Hough, Fellow of St. John's College, Cambridge, who has 

 recently been appointed chief assistant at the Royal Observatory, 

 Cape of Good Hope, visited the Observatory from August 18 to Sep- 

 tember 1, in order to gain a knowledge of the method of observing 

 with the Unifilar Magnetometer and Inclinometer. 



At the request of Professor Moos, director of the Colaba Ob- 

 servatory, Bombay, copies of the horizontal force, the vertical force^ 



B 2 



