[ 335 ] 
IX. A/i A?ic///ysi.s of the Results from the Kew Alagnetographs on “ Quiet" Days 
during the Eleven Years 1890 to 1900, with a Discussion of Certain 
Phenomena in the Absolute Observations. 
By Charles Ciiree, Sc.D., LL.D., F.R.S., Siqyerintendent of the Observatory 
Department o f the National Physical Laboratory. 
[From the National Fhysiccd Laboratory.) 
Eeceived May 1,—Eead May 28, 1903. 
Contents. 
Sections f*‘ige 
1. Introduction. . .... 33-0 
2. MMlf and 5 Volfer’s sun-spot frequency data.336 
3-9. Secular change .... 337 
10-12. Annual inecpiality.344 
13-17. Non-cyclic etfect.346 
18-28. Solar diurnal inecpiality, tables and their discussion.35-5 
29, 30. Curves representing diurnal inequality.37.0 
31-36. Eepresentation of diurnal inecpialities by Fourier series.380 
37, 38. Variation of ranges, &c., throughout the year, treated liy means of 
Fourier series.394 
39,40. “ Variability ” of the declination.397 
41. Sun-spot relations. Introduction.399 
42-44. Variation of declination and horizontal force ranges with suu-sjiot 
frecpiency.399 
45-47. Curves illustrative of sun-spot relations.402 
48, 49. Sun-spot relations apparent in Fourier coefficients.406 
50-60. Sun-spot formula; numerical relationships.415 
61-70. Eelations with meteorological phenomena.426 
71-76. Nature of the relationship between sun-spots and terrestrial magnetism. 
Speculations.433 
§ 1. In 1'889 the then Kew Committee agreed to take part in a scheme which 
provided that at the end of each year the Astronomer Royal should select five 
magnetically (pact days for each month with a view to the tabulation of their records. 
Tlie scheme has been in continuous operation since 1890, and the results from tlie 
VOL. COIL—A .854. 10.12.03 
