TRANSACTIONS OF THE SECTIONS. 



6i 



number of cases in hospital suffering from cholera, dysentery, diarrhoea, and inter- 

 mittent fever. 



These forms were filled in and forwarded monthly to the author, who prepared an 

 annual report on the whole. 



The results (to state them as briefly as possible) of the four years' registration 

 go to prove that practically the same conditions of atmosphere are present in 

 India as in Europe when the full manifestation of atmospheric ozone is present. 

 Elevation above the sea-level, the prevalence of the equatorial current, proximity 

 to the ocean, and prevalence of sea breeze, a certain amount of moisture, the fall 

 of rain, hail, and dew, the occurrence of thunder-storms and dust columns, or other 

 indications of excited electrical conditions, all influence the evolution of ozone 

 alike in India as elsewhere. Thus at the station of Mahableshwur, vrhich is 

 4500 feet above the sea, the daily mean average of ozone is 7 of the scale. At 

 Belgaum, in the southern Mahratta country, and at Poonah and Sattara in the 

 Delikan, at heights from 1500 to 2000 feet above the sea-level, the average is from 

 43 to 5-5, while in the northern division (the mean distance from the sea of the 

 three stations which it includes being 194 miles) the average falls slightly below 

 2'0 of the scale. 



During the prevalence of the S.W. winds and the rainfall of the monsoon 

 season, while the great equatorial cun'ent is sweeping up from the ocean to the 

 south, high averages are obtained, varying from 3'5 to 5-3 as a mean for all 

 stations ; but during the pre'^'alence of the north-easterly or polar current, from 

 November to March inclusive, the average monthly mean falls to 26 or 29. 



The influence of these winds on the presence of atmospheric ozone is shown in 

 the Table, where the returns of four consecutive years are grouped. 



Table giving the Mean Monthly Quantities of Atmospheric Ozone deduced from 

 registration of four years at the several Stations. 



The mean average for each month of the year, obtained from the results of all 

 stations, is here shown in .separate columns for each year, and the mean for each 

 month deduced in the last column. The prevailing winds for every month are 

 also given. The Table, therefore, contains the broad results of the four years of 

 registrations. 



The occurrence of occasional storms of thunder and rain during the dry weather 

 of the cold and hot seasons is always marked by a sudden and decided increase 

 in the amount of ozone, appreciable by the resulting coloration of the test-paper, 

 and the dust-stonns ; and other remarkable indications of electrical disturbance, 

 which so frequently occur in the Dekkan and in Scinde, have a like, though less 

 mai-ked effect. 



A diagram was shown giving the curves of average monthly mean qiiantities of 

 atmospheric ozone for four years, an attempt being made to exhibit at a glance 

 the chief results obtained by the registration of these years, and the causes which 

 chiefly influence the depression of the ozone-line below its normal position. 



The chief causes which influence the depression of the ozone-curve appear to be, the 

 dryness of the atmosphere, the occun-ence of the land wind or N.E. or polar cur- 



1869. 5 



