MR. J. BAXENDELL ON ATMOSPHERIC OZONE. 199 



Observations at the Melbourne Observatory, 



During the years 1858-60, and again during 1863-65, 

 ozone observations were made at the Melbourne Observa- 

 tory by Mr. Robert J. EUery, the Government Astronomer. 

 Grouping the monthly means according to the seasons, we 

 have — 



Winter 5*25 



Spring 4*i6 



Summer 3'6o 



Autumn 4*14 



Here the maximum occurs in the winter and the mini- 

 mum in the summer quarter, the character of the changes 

 thus agreeing almost exactly with that shown by the Lis- 

 bon observations. 



The annual values are — 



1858 36 1863 4-5 



1859 4*4 1864 4*6 



i860 4-5 1865 5-1 



4"i7 4*73 



The mean for the three years of maximum solar-spot 

 frequency is 4* 17, and that for the three years of minimum 

 is 473, the difference being 0*56, thus showing an action 

 precisely similar to that shown at Hobart Town and at 

 Oxford. 



Ozone observations were made at the Sydney Observa- 

 tory during the four years 1860-63, but I have not yet 

 been able to meet with the details. The annual amounts, 

 however, were — 



i860 6-15 



1861 5"20 



1862 423 



1863 4-00 



Here we have a gradual diminution of the amount of ozone 

 corresponding to a gradual decrease in the frequency of 

 solar spots, thus exhibiting a character similar to that 



