154 ; REPORT—1849. 
Low tension.—In the following table, which exhibits the distribution of 
low readings in each month of the three years, the greater number during the 
summer is very apparent ; it will be remarked that July presents the greatest 
number and February the least; the proportion is nearly as 3 to 1. 
TaBLeE LIX. 
Number of positive readings below 60 div. in each month of the three years 
1845, 1846 and 1847. 

: Year.) J an. Feb.|Mar.| April. May. June.) July. |Aug.| Sept. | Oct.|Nov.| Dec./Sums. 



| 1845.|184|107| 145} 211 | 257} 277 | 315 | 287) 271 | 206/113) 149 | 2522 
1846.| 146 | 109 | 152} 172 | 268; 280 | 306 | 297) 291 | 198/193) 73 | 2485 
1847.| 79 83 | 167 190 | 289; 291 | 273 | 292) 279 | 253} 174 | 152 | 2522 
mm | | | | | | | FT 
as] 
‘Sums. 409 |299 | 464 573 814 | 848 | 894 | 876] 841 | 657 | 480 | 374 | 7529 
TABLE LX. 
Mean electrical tension below 60 div. of each month in the three years 1845, 
1846 and 1847, with the mean annual period, as deduced from all the posi- 
tive readings below 60 div. 
May.) June. | July. Aug.| Sept. | Oct.|Nov.) Dec.| Mean. 
aes ele ay OTL ei It ee ar 
div. | diy. | div. | div. | div. | div. | div. | div. / diy. | diy. | diy. | div. | diy. 
| 1845.) 25:8) 30°7| 28-7} 29-0 | 25°2) 21:5 | 22°5 | 24:0) 27-5 | 25°6) 32+4| 28-6] 25°9 
1846.) 34°7| 34-6) 35°1| 31:3 | 27°5| 26°8 | 28°5 22:3| 22°8 | 33°3|.30°7| 37-3) 28:8 
| 1847.) 38°8] 36°2) 35:2) 35°3 | 27-4 27°6| 36°4 | 28°7| 28°5 | 26°2/ 31°8) 35:0) 31-1 
26:2 | 28-1 31+5| 32°9| 28°6 
Year.| Jan.) Feb.|Mar.! April. 











|Mean.| 31°5| 33°7| 33°1) 31:8 | 26°8; 25-4 | 28-8 | 25-0 







TaBLeE LXI. 
Excess or defect of the mean electrical tension below 60 div. of each month, 
as compared with the mean of the years for the three years 1845, 1846 
and 1847, and the mean annual period. 




Year.) Jan.| Feb.|Mar,| April.|May.| June.|July.|Aug.| Sept. | Oct.|Nov.| Dec.|Mean. 
~/+/4+/4+])/-]}-/-|-|+/])-/4]4 
1845.) 0:1 |4°8 |2°8 | 3:1 [O07 | 4:4 | 3-4 | 1:9 | 1:6 | 0°3 | 65 |2°7 | 25°9 
fe RA ee ea —o) — | See ae 
1846.) 5°9 |5°8 (6:3 | 25 | 1:3 | 2:0 |03 | 65 | 60 | 45 |1-9 |85 | 28:8 
+}/+/+}/+)-]|-/4\/-|-|-|4+/4+ 
1847.) 7°7 | 5:1 [4:1 | 4:2 [3:7 | 3:5 | 5:3 | 2:4 | 26 14:9 10-7 13:9 | 311 
+/+)+/+4)/-]-)/4/]-|-/-/4+]/+ 



Mean.| 2°9 | 5-1 | 4°5 | 3°2 |1°8 | 3:2 | 0-2 |3°6 | 2-4 105 | 2:9 | 4:3 | 28:6 
In the above tables we see an annual period nearly similar to that deduced 
from the entire series of positive observations during the three years. The 
main feature—that of an increase of electrical tension in the winter and a 
decrease in the summer—is the same in both periods ; and from this cireum- 
stance the legitimate inference is, that the low tensions are affected by the 
presence of aqueous vapour as well as the high ; consequently the arbitrary 
division at 60 div. fails at all seasons entirely to separate the electricity of 
aqueous vapour from that of the atmosphere, supposing the true march of 
the latter to be in harmony with that of the temperature. There are some 
minor differences between the two periods which it may be interesting to 

