116 Senhor Capello and Mr. B. Stewart — Comparison of [Jan. 28^ 



The following Table exhibits approximately the proportion between the 

 disturbance-waves of the horizontal force at Lisbon and at Kew. 



Table III. 



Date. 



Proportion between the disturbance-waves of 

 the horizontal force reduced at both places 

 to English units (Lisbon wave = unity). 



July 15. 



Variable between 1 : 



1*3 and I 



: 1*9 



16. 



» 



1 : 



1-8 and 1 



:* 1-9 



17. 



>> 



1 : 



1-6 





18. 



»i 



1 : 



1-9 and I 



: 2-5 



19. 



»> 



1 : 



1-7 





20. 



» 



1 : 



1-5 and 1 



: 20 



21. 



a 



1 : 



1-5 and 1 



: 20 



22. 



yy 



1 : 



1-7 





23. 



jj 



1 : 



2-0 





24. 



jj 



1 : 



2-0 







Mean . 



. 1 : 



1-8 





From this Table it will be seen that while this proportion is variable, yet 

 one may generally regard the disturbing force at Kew as greater than that 

 at Lisbon in the proportion of 1*8 to 1. 



2. Declination {east and west disturbing force), — The declination- 

 curves for Kew and Lisbon are very like each other, and the waves as well as 

 the peaks and hollows are for the most part simultaneously produced in the 

 two collections of curves. Since, however, at Kew the waves are greater, 

 one does not always easily perceive the resemblance. Certain peaks or 

 waves very prominent at Kew, are reproduced but slightly at Lisbon ; but 

 a careful scrutiny shows that all, or very nearly all, of the Kew waves and 

 peaks occur at Lisbon also. 



In Table IV. we have a comparison of the principal points of the decli- 

 nation-curves with respect to time. From this Table it will be found that 

 the average difference between the local times of corresponding points is 

 34"'-0, that due to difference of longitude being 35™-3. 



The following Table exhibits approximately the proportion between the 

 disturbance-waves of the declination at Lisbon and at Kew. 



Table V. 

 Proportion between the disturbance-waves 

 Date. of the declination reduced at both places 

 to English units (Lisbon wave=unity}. 



July 15. Variable from 1 : 1-8 to 1 : 2-1 



16. „ 1 : 1-5 



17. „ 1:1-4 to 1:1-6 



18. „ 1:1-5 



19. „ 1:1-5 



20. „ 1 : 1-7 



21. „ 1 : 1-3 



22. „ 1:1-4 



23. „ 1:1-8 



24. 1 : 1-6 



Mean 



1 : 1-6 



