AND THEIR CONNECTION WITH MAGNETIC CHANGES. 



363 



TABLE IV. — Hourly Means op the Earth-Cukrents observed on the London and Dover 



Line during Magnetic Calms. 



0". 



11". 



S". 



41^. 



5i>. 



6^. 



8^. 



g^. 



10''. 



ll''. 



12'>. 



i3i>. 



UK 



ISi. 



16^. 



17''. 



ISi-. 



ig*. 



2011. 



21\ 



22''. 



2 



3 



2 



5 



4 



4 



6 



5 



24 



13 



3 



2 



3 



+ 14 



-27 



-29 



-23 



-28 



^20 



-21 



-^16 



-7 



+ 3 



+ 18 



-20 



+ 4 



231'. 



iber of ob- ] 

 vations, . J 

 a value of 1 

 •rent, . . 



12 

 + 34 



3 



+ 50 



9 



+ 29 



11 



+ 19 



3 



+ 15 



3 



-23 



4 I 

 + 17, 



'ABLE V. — Hourly Means op the Earth-Currents observed on the London and Tonbridge 



Line during Magnetic Calms. 





0^. 



1". 



21'. 



Sh. 



4". 



51^. 



6\ 



7^. 



St. 



gh. 



lot. 



111-. 



UK 



13h. 



141^. 



ISi. 



Ifih. 



17\ 



ISi. 



igi*. 



20''. 



21''. 



22''. 



23''. 



iber of ob- 1 

 vations, . J 

 1 value of 1 

 ■rent, . . 



11 



-30 



5 



-.17 



9 



-24 



10 

 ^16 



3 



-22 



3 



-23 





2 

 + 10 







2 

 -9 



3 



+ 3 



2 

 ^20 



6 

 -.12 



3 

 -6 



4 



-7 



6 

 + 3 



5 



+ 7 



23 

 -3 



15 

 + 1 



4 

 + 2 



3 



+ 18 



3 



+ 16 



5 

 -17 



'ABLE VL— Hourly Means op the Earth-Currents observed on the Tonbridge and Dover 



Line during Magnetic Calms. 





0''. 



lb. 



2h. 



3". 



4»'. 



5". 



6''. 



7". 



8i». 



9h. 



10''. 



IH'. 



12''. 



13''. 



14''. 



ISi". 



16''. 



17''. 



18". 



igi'. 



20''. 



21''. 



22". 



23". 



I her of ob- "1 

 5 rations, . / 



14 



4 



7 



11 



3 



3 





2 







3 



2 



3 



4 



4 



4 



6 



5 



26 



18 



4 



2 



4 



4 



SI value of\ 

 crent, . . J 



+ 68 



+ 39 



+ 32 



+ 26 



+ 18 



-13 





-63 











-2g 



-34 



-2g 



-36 



-27 



-2g 



-25 



-.8 



-2 



+ 2 



-17 



+ 7 



+ 32 



It will be seen that each of these tables exhibits a daily period, and that in 

 each the values of the currents for the hours of the day are greater than those 

 for the hours of the night. 



Also we may regard the means for 0^ 2^ 3^, 18", 19 '',as being best determined. 



Let us employ the following method as perhaps the best in our power for 

 exhibiting the characteristic difference between the three classes of earth-currents. 

 Let us represent in a tabular form the departures from the means above given of 

 the individual observations of each of these classes. 



VOL. XXIII. PART II. 



O G 



