237 
“ In 1872 I had a series of observations made twice daily 
for five weeks at stations on opposite sides of one of the 
reservoirs of the Manchester Corporation Water Works, and 
grouping the results according to the direction of the wind, 
I found that the mean values for the station on the lee side 
of the reservoir were not sensibly different from those at 
the station on the windward side.” “The results of the 
observations clearly indicated that mere evaporation from a 
large continuous surface of water had no effect in increasing 
the amount of ozone in the air passing over it. Observations 
and experiments made at Southport, on the action of spray 
from the sea, led to no satisfactory result, on account of the 
difficulty of eliminating the effects due to varying velocities 
of the wind. I had long been anxious to try the effects of 
spray from a large fountain, but had no opportunity of doing 
so until June last.” Then, after describing the opportunity 
and the experiments made, he says, “Having now proved 
experimentally that spray produced by mechanical means, 
and ordinary fog or haze produced by the condensation of 
aqueous vapour in the air are precisely similar in their re- ' 
lations to atmospheric ozone, and having also shown that 
the quantity of ozone usually found in the air could not 
have been held in solution by the water from which the 
aqueous vapour in the atmosphere is derived, it becomes 
evident that the production of atmospheric ozone is in some 
way dependent upon the minute state of division in which 
water exists in the air in the visible form of clouds, fogs, 
and haze, and often also, probably in an invisible form. This 
conclusion has led me to infer that water exposed to the air 
has the power of condensing oxygen upon its surface into a 
thin film of ozone.” “ Admitting that the inference I have 
drawn from the facts given in this paper is correct, it will 
enable us to explain why, on the sea coast, winds from the 
sea bring more ozone than those from the land.” 
Here then for the first time is set forth the results of ex- 
