ON ELECTRICAL OBSERVATIONS AT KEW. 145 
maxima in the winter of 1847. We 
see at a glance how greatly the 
forms of the aggregate curves de- 
pend on the higher tensions. On 
comparing the two series with those 
of the entire year (aggregate ten- 
sion), the influence of the high ten- 
sions upon the whole is readily 
traced. We see the winter curves of 
high tension strongly influencing the 
winter curves of aggregate tension, 
and these again the aggregate of the 
entire year, the threeseries of curves 
closely resembling each other. The 
influence of the high tension entire 
year on the curves of aggregate ten- 
sion for the same period is not so 
1845. 

1846. striking ; the summer readings mo- 
. dify the curves, and illustrate the 
S remarks we have already offered on 
a the variability of the point of sepa- 
G: ration. 
1847. 
. 
3 Winters. 

Mean diurnal curves of the electrical tension above 60 diy. for the winters of 1845, 1846 and 1847, with the mean curve of the three winters. 
4A.M. 10 A.M. 10 P.M. 2A.M. 
i E 
= =) 
_-Tasix XLIV. 
Comparison of the excess or defect from the mean of the diurnal periods of 
winter, as deduced from the aggregate observations and from those above 
_. 60 div. 
Value. Mid.|2 a.m.|4 a.m.|6 a.mn.|8 a.m.|10 a.m.|Noon.|2 p.m./4 p.m./6 p.m.|8 p.m.|10 p.m.|Mean. 
— |E ——_$J| | — | — |X ——_ | | 

— | - +|-|-|-] 4+ {4+ 
- | 92°0 | 25°0 ita 84 117-0 |28°9 | 3:3 | 25-4 | 15:7 /197°9 
L 

