492 Report of the Kew Committee. 



Balance, January 13, 1890 for 1 inch oV= 0*0296 foot grain unit. 



I cm. = 0-00054 C.G.S. unit. 



In the case of the vertical force magnetometer, it was found neces- 

 sary to re-adjust the instrument, and as at the same time its sensi- 

 bility was slightly altered, the scale value was again determined, with 

 the following result : 



Balance, January 21, 1890, for 1 inch 3V= 0'0284 foot grain unit. 



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



With regard to magnetic disturbances, no very exceptional move- 

 ments have beeu recorded during the year. 



The principal disturbances were on the following dates : November 

 1 and 2628, 1889. 



The monthly observations of Horizontal Force, Inclination, and 

 Declination with the absolute instruments have been made in accord- 

 ance with the usual practice. 



Information on matters relating to terrestrial magnetism and 

 various data have been supplied to Professors Thorpe and Riicker, 

 Dr. van Rijckevorsel, Dr. Atkinson, Professor Chistoni, and Captain 

 Schiick. 



Magnetic Sub -Committee. Professors W. G. Adams, A. "W. Riicker 

 and Captain Creak having been requested by the Committee to act as 

 a sub-committee to consider the form to be employed in framing the 

 appendices to this Report, have held two meetings. They decided 

 that in future the Magnetic and Meteorological Appendices should 

 be presented to the Royal Society as soon after the 1st of January 

 as possible, instead of accompanying the Report itself, and therefore 

 closing with September 30th as heretofore. This arrangement will 

 take effect with the present issue. 



At the suggestion of Professor Riicker, the Kew Magnetical Decli- 

 nation results for the years 1883, 1886, and 1887 have been recently 

 discussed in a paper published by the Physical Society of London in 

 their Proceedings, entitled " On the Diurnal Variation of the Magnet 

 afc Kew," by Messrs. Robson and Smith. These gentlemen, students 

 in the physics class at the Royal College of Science, kindly gave their 

 assistance in the labour of tabulation and computation. 



At the request of Professors Thorpe and Riicker, facilities have been 

 afforded to Messrs. Gray and Briscoe, who are also attached to the 

 physical laboratory in the Royal College of Science, South 

 Kensington, to make magnetic base observations from time to time at 

 Kew, with the view of their employment in the Magnetic Survey of 

 Great Britain and Ireland now in progress on a more extended scale 

 than that on which it has before been carried out. 



