THE FORMATION OF OZONE IN THE 

 UPPER ATMOSPHERE, AND ITS IN- 

 FLUENCE ON THE OPTICAL PRO- 

 PERTIES OF THE SKY 



By J. N. PRING, D.Sc, University, Manchester 



Part i. Some Factors which determine the Optical Properties of the Atmosphere 

 Part 2. The Chemical Estimation and Distinction of some Constituents of the 



Atmosphere 

 Part 3. The Action of Ultra-violet Light on Air 



Part 4. The Estimation of Ozone in the Atmosphere at High Altitudes 

 Part 5. The Influence of Ozone on the Nature of Light from the Sky 



Part i. Some Factors which determine the Optical 

 Properties of the Atmosphere 



The importance of the question of the presence of ozone in the 

 air is due to the large influence which would be exerted by- 

 its occurrence, though only in small amounts, on the physical 

 and chemical properties of the atmosphere. From the chemical 

 standpoint the importance of ozone centres in its powerful 

 oxidising properties, in virtue of which the gas, even when 

 diluted, quickly reacts with all organic matter, and acts as a 

 strong bactericide. In this way ozone would be expected to 

 take an important part in the purification of the atmosphere 

 and in determining the salubrity of the climate. From a 

 physical standpoint, its presence is mainly of interest on 

 account of the influence it would exert on the transmission 

 of light radiated from the sun. The absorption of light by 

 ozone is particularly marked in the ultra-violet region of the 

 spectrum. It has indeed been found by photo-electric measure- 

 ments that in a column of gas 16 cm. long, a quantity of ozone 

 amounting to only 0*001 per cent, can be detected by measuring 

 the intensity of light transmitted. The particular wave-length 

 for which this absorption is a maximum has the value 258 yu.//., 

 while the band extends from about 200 to 300 /*//.. These values 



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