26 
A projection of the numbers in the last column is shown 
in curve No. 3, and it will at once be seen that this curve 
differs altogether in character from the curves for Eccles 
and Oxford, the maximum occurring in November and the 
minimum in July, thus showing clearly that the monthly 
amounts of ozone have no dependence upon the monthly 
amounts of solar radiation. 
t 
The mean amounts of ozone at Lisbon in the different 
seasons are : 
Winter 5 ’40 
Spring 5*16 
Summer 3’83 
Autumn 4 '9 3 
The maximum therefore is in the winter, and the mini- 
mum in the summer quarter. I may also remark that 
while at Eccles and Oxford the maximum rises higher above 
the mean of the year than the minimum falls below it, at 
Lisbon the reverse of this takes place, the difference between 
the maximum and mean values being less than between the 
minimum and mean. 
Taking now the annual amounts, we have : 
1856 ... 
... 4*4 
1860 ... 
... 5-4 
1857 ... 
... 5-2 
1861 ... 
... 4-7 
1858 ... 
... 4-7 
1862 ... 
... 4*6 
1859 ... 
... 5-1 
1863 ... 
... 4*6 
Dividing these numbers into two groups according to solar 
spot frequency, and taking the means, we have : 
Mean annual amount of the four years 1858-61, 
when the number of solar spots was above the 
average . 4-97 
Mean annual amount of the years 1856-7 and 
1862-3, when the number of solar spots was 
below the average . 4-70 
0-27 
