716 



SEC. 14. METEOROLOGY. 



Mean of all the hours = 2 63, 



2906. Aspirator, with gutta percha tubing and wooden box 

 for tests, used by the Ozone Committee during their experiments 

 in 1869. Scottish Meteorological Society. 



The small tin box was made by a native Arab for Dr. Arthur Mitchell, in 

 connexion with ozone experiments made by him in Algiers in 1855. 



2907. First Ozone Generator. Dr. Werner Siemens. 

 The air or oxygen to be ozonised is caused to pass between two concentric 



cylinders coated with tinfoil, and electrified by an induction apparatus. 



2907a. Tisley's Ozone Generator. The central tube being 

 used as a water channel, a uniform low temperature can be main- 

 tained, thereby greatly improving the per-centage of ozone. 



Tisley and Spiller. 



See "Nature," 19th June 1873. 



