relation to Electrical and Magnetic Phenomena. 143 



Table I. — Mean Values of the Terrestrial Currents observed 

 between Rome and Anzio at the College Romain. 



Date. 



Time. 





















7 a.m. 



9. 



10.30. 



Mid- 

 day. 



130 | 3. 



P.M. 



5. 



7. 



9. 



10. 



1863. 



















May 25 to 28' 4-63 



60 



75 



6-20 



5-53 3-85 



4-3 



413 



4-33 



4-70 



Aug. 10 to 311 7-31 



912 



9-91 



8-90 



7-16 6-98 



658 



700 



7-37 



7-86 



Sept. 1 to 30 6-90 



7-80 



9-9 



8-3 



6-78 6-43 



6-92 



667 



676 



711 



Oct. 1 to 18i 8-1 



8-42 



-9-26 



8-17 



7-74 6-28 



6 25 610 



6-27 





Nov. 6 to 30 15-62 



14-15 



13-77 



13-87 



9-31 14-52 



1513 11-31 



11-8 



15 30 



Dec. 1 to 171 13-84 



11-3 



11-93 



1215 



11-45 11-57 



1015J 11-48 



11-86 





1864. 











1 











Jan. 1 to 31 



8-79 



8-95 



8-85 



8-97 



8-42 1 7-78 



815 



8-56 



8-65 





Feb. 1 to 29 



7-56 



8-2 



8-57 



8-81 



7-98 7-21 



7-20 



6-73 



735 





Mar. 1 to 31 



6-87 



8-93 



10-5 



9-55 



6-65, 6-21 



6-72 



7-75 



7-95 





Apr. 1 to 24 



5-42 



8-6 



8-75 



721 



5-55 5-34 



4-45 



6-34 



6-52 



By this long series of observations, the diurnal period with its 

 principal minimum in the morning between 7 and 9 o' clock, 

 and the maximum near midday, is seen to be confirmed ; but 

 the influence of seasons tells, for there is anticipation in sum- 

 mer, and retardation in winter. 



Although the absolute value of the current does not enter 

 into our discussion, the enormous increase which is attained 

 during the last quarter of 1863, and especially in the month of 

 November, must not be overlooked. 



It is interesting to compare these variations with those of the 

 horizontal force. 







Table II.- 



-Indications of the Bifilar. 









Time. 



Therm. 



Date. 



























7 a.m. 



9. 



10.30. 



Mid- 

 day. 



1.30. 



P.M. 



3. 



5. 



7. 



9. 



10.30. 



[ Fahren- 

 heit. 



1863. 

























May 



134-4 



133-7 



136-9 



1360 



137-4 



135-4 



136-5 



135-4 137-4 



136-7 



66-95 



Aug. 



125-4 



1230 



124-6 



1269 



127-9 



127-4 



1275 



1281 128-7 



129-7 



79-30 



Sept. 



127-2 



124-7 



126-5 



127-9 



129-9 



128-2 



124-5 



128-9 129-3 



128-4 



7642 



Oct. 



1390 



135-9 



134-7 



135-7 



136-9 



135-7 



137-7 



137 3! 138-7 







69-63 



Nov. 



149-9 



147-3 



1469 



146-3 



144-4 



144-3 



1448 



145-9 147-4 



148-8 



62-92 



Dec. 



160-7 



155-7 



157-9 



157-2 



156-2 



155-4 



1561 



1571 



157-3 



158-6 



5312 



1864. 

























Jan. 



96-6 



94-2 



93-9 



92-2 



93-3 



92-6 



929 



93-3 



93-7 





4767* 



Feb. 



96-8 



94-1 



92-2 



91-7 



92-9 



92-4 



92-4 



93-3 



94-2 





49-47 



Mar. 



87-5 



84-9 



83-6 



83-9 



84-8 



84-4 



856 



85-6 



85-8 





55-84 



Apr. 



85-7 



82-4 



83-7 



86-7 



870 



85-9 



85-6 



86-9 



87-4 



86-5 



53-98 



* The scale changes at the beginning of the year. 



