115 
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 Waterworks, and, 
grouping the results according to the direction of the wind, 
I found tliat 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 surface of the 
water was, however, seldom sufficiently disturbed to produce 
any appreciable amount of spray ; but 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 ; but the influence of fogs 
and haze in checking the coloration of the test papers was 
very marked. 
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, when I became aware for the first time of the 
existence of the fine fountains at the Arnfield and Holling- 
worth reservoirs in the Manchester Corporation Water- 
works' district. In both these fountains the diameter of 
the column of water as it issues from the discharge pipe is 
nine inches, and under full pressure the height of the 
column or jet is about 27 feet at Arnfield, and 35 feet at 
Hollingworth. The water is turned on at ' very irregular 
intervals, and generally for only short periods of time, but 
with the kind assistance of Mr. James Wilkins, the very 
intelligent reservoir-keeper, and observer at the Arnfield 
meteorological station, I succeeded in making a satisfactory 
series of experiments, the details of which are as follows : — 
For the exposure of the test papers two open boxes were 
used, each about 2 feet long, 10 inches wide, and 4 inches 
