196 MR. J. BAXENDELL ON ATMOSPHERIC OZONE. 



Night, Day. Mean. 



January 5*8 5*1 5*4 



February 5*8 5*2 5*5 



March 5*8 5-0 5*4 



April 5'8 4-8 5-3 



May 53 4'3 4'8 



June 47 3-8 43 



July 3*8 3-0 3-4 



August 4-4 3*3 3-8 



September 47 3*8 4*3 



October 5*3 4*5 4*9 



November 6'o 5*3 5*6 



December 57 5*0 5*3 



Year 5-3 44 4-8 



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. 



The mean amounts of ozone at Lisbon in the different 

 seasons are ; — 



Winter 5*40 



Spring 5-16 



Summer 3*83 



Autumn 4*93 



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 i860 5'4 



1857 5-2 1861 47 



1858 47 1862 4*6 



1859 ..... 5'i 1863 4-6 



