532 Dr. Barker on the relative value of the 



Table {continued). 



A few brief remarks may serve to indicate the importance of 

 the results thus obtained. 



During the eighteen months over which the observations ex- 

 tended, there were 122 days in which Schonbeiu's paper indicated 

 the presence of ozone ; while there were 207 days in which 

 Moffat's papers were discoloured. In other words, in 85 days, 

 out of 207, Schbnbein's papers failed to record the action of 

 ozone ! On the other hand, Moffat's papers never failed to 

 receive a tinge when Schonbein's indicated ozone. It is true, 

 on one occasion (October 31st, 1855) Schonbein's papers were 

 more deeply tinged than Moffat's; but this may safely be 

 passed over as a mere accident, when weighed against the 

 contrary results of 197 observations. 



The total amount of ozone indicated by Schonbein's paper, 

 during the entire period of observation, is represented by the 

 number 351, while Moffat's paper registered 793. 



The mean monthly amount by Schonbein's was 19*50; by 

 Moffat's 44-05. 



