162 Report of the Kew Observatory Committee. 



The work at the Observatory may be considered under the fol- 

 lowing heads: 



1st. Magnetic observations. 

 2nd. Meteorological observations. 

 3rd. Solar observations. 



4th. Experiments and Researches in connexion with any of the 

 departments. 



5th. Verification of instruments. 



6th. Hating of Watches and Marine Chronometers. 



7th. Miscellaneous. 



I. MAGNETIC OBSERVATIONS. 



The Magnetographs have been in constant operation throughout 

 the year, and the usual determinations of the Scale Values were made 

 in January. 



The ordinates of the various photographic curves representing 

 Declination, Horizontal Force, and Vertical Force were then found 

 to be as follows : 



Declinometer : 1 inch = 22''04. 1 cm. = 8'7. 



Bifilar, January 20, 1897, for 1 inch H = O0280 foot grain unit. 



1 cm. = 0-00051 C.G.S. unit. 

 Balance, January 21, 1897, for 1 inch oV= 0'0274 foot grain unit. 



1 cm. = 0-00050 C.G.S. unit. 



During the past year the magnetic curves have been free from any 

 very large fluctuations. The principal variations that were recorded 

 took place on the following days : 



January 2; February 4, 2527; March 910; April 2, 20, 

 2324 ; May 17 ; June 1617 ; July 31 ; October 12, 28 ; Novem- 

 ber 17; December 11, 2021. 



The hourly means and diurnal inequalities of the magnetic elements 

 for 1897, for the quiet days selected by the Astronomer Royal, will 

 be found in Appendix I. 



In the present year a correction has been applied for the diurnal 

 variation of temperature, use being made of the records from a 

 Richard thermograph as well as the eye observations of a thermo- 

 meter placed under the Vertical Force shade. 



The mean values at 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 6''4. 



Mean Horizontal Force 0'18342 C.G.S. unit. 



Mean Inclination 67 19''6. 



Mean Vertical Force . . 0'43906 C.G.S. unit. 



