160 REPORT—1849. 
made. - The minimum tension at sunset occurs in August (value 39°3 div.), 
and is sueceeded in September and October by a gentle and regular increase. 
From October to January the increase is very rapid, but at the same time 
very regular, so that the curve possesses a bold flowing character, the as- 
cending branch being free from interruptions arising from sudden starts in 
Fig. 17. 
ee oe Me MA 



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el india llsiina| Sobaalamg 
i Sc aS A eee 
iTSaN a 
= Lilt | \ 80 
Mean. i 
is eae pee AN ANU Sil eae 
Mem. 1 | ad tae aaa ae lke Be ners: 
ae ae ead ep a a ee 
Mean Fis A aa I SA FE a fe 
Sunrise. , Mean. 
kg a =a a i es Hl bid = 
| | | Sunrise, 
10 | | 10 
isa) og 
0 e 
Gods) SockOnuNs., Dio cde Be cele \ Beg Mix foe 
i i he electrical tensi { sunrise, sunset, and the mean from 
Curves representing the annus) Pe pecrvations of 1845, 1640 and 1847. 
the movement, or from sudden and irregular increments of tension. The 
apex which occurs in January is well-marked and acuminated in its character, 
and the portion of the descending branch immediately succeeding it is toa 
great extent symmetrical with the corresponding portion of the ascending 
branch, and this symmetry obtains at least between the months of Novembes 
and March. The entire diminution of tension from January to June presents 
precisely the same characteristics as the increase from August to apenehe 
viz. regularity of decrement, giving to the curve a flowing character, whic 
in consequence of the large differences in the monthly tensions also possesses 
considerable boldness. 
The mean annual curve derived from the observations of 1845, 1846 aa 
1847, differs from the curve just examined in two or three minor particulars. 

