350 ADDENDA. 



also showed that the presence of ozone was most apt to be detect- 

 ed in winds with southing in them, or, as Jansen expresses it, in 

 winds that come from toioard the equator. The doctor found 

 slight or no traces of it in winds coming from toward the pole. 

 In other words, the observations of these two philosophers go to 

 show that ozone is most abundant, in the northern hemisphere, 

 in winds that have southing in them ; and in the southern hem- 

 isphere, in winds that have northing in them. 



*' Straws show which way the wind blows," but to follow it in 

 its cicruits we must avail ourselves of things lighter than straws. 

 According to these observations, the great atmospherical labora- 

 tory for the supply of ozone to the winds must be somewhere in 

 the equatorial regions of the air, or over the phosphorescent waters 

 of the sea, which most abound in intertropical regions. One 

 school of philosophers hold that ozone is produced by thunder and 

 lightning. If so, then where will you find such a laboratory for it 

 as among the detonations, and clouds, and rains of the equatorial 

 calms ? The electrical machinery of the equatorial cloud-ring is 

 in ceaseless activity ; and if it be the fountain of ozone in the at- 

 mosphere, how can the ozone cross the trade-wind regions except 

 with the upper currents ? And when the air of this upper current 

 descends, in the calms of Cancer and of Capricorn, to make surface- 

 winds of, why, unless this same air continued on toward the poles, 

 should the ozone be found in it and not in the trades, or the wind 

 from toward the pole ? 



If, at the meeting of these two upper currents, there were not a 

 crossing, but a mingling, why should not the presence of ozone be 

 as well marked in the winds that come out on the equatorial, as it 

 is in those that come out on the polar side of the calm belts of 

 Cancer and Capricorn ? 



This chemical substance, like magnetism, sea-dust, etc., is a 

 gossamer-like clew, indeed, to the path of the winds ; but, as far as 

 we can trust these little threads, or follow them up, they seem all 

 to lead through the mazes of the calm belts, and to come out on 

 the side opposite to that on which they entered.* 



* Dr. Breed, of Washington, has veiy kindly furnished me with the following rec- 

 ipe for ozone paper : 



