67 
or district is indicated by the greater or less amount 
of free ozone usually present in the atmosphere, and the 
results of occasional comparisons of the observed amounts of 
ozone with the rates of mortality have generally tended to 
support this view; but in order to ascertain clearly the 
nature and extent of the connection between the amount of 
ozone and the rate of mortality, it is evidently necessary 
that before comparison with the rate of mortality is made* 
the registered results of ozone observations should be cor- 
rected for the effects of the various meteorological causes 
which are known to influence the observed amounts of 
free atmospheric ozone. Among these causes, the velocity 
of the wind is by far the most important. Other things 
being the same, the greater the velocity of the wind and the 
greater will be the registered amount of ozone. I therefore 
calculated the mean daily velocity of the wind for the nine 
years 1872 — 1880, from the observations taken with the 
Eobinson anemometer mounted by Mr. Dancer at the South- 
port Meteorological Observatory, and as I had found that 
the variations in the recorded amounts of ozone are approxi- 
mately proportional to the variations in the mean daily velo- 
city of the wind, I calculated the corrections necessary to be 
applied to the observed amounts of ozone to reduce them to 
what they would have been had the mean velocity of the 
wind been the same in every year. The data used in the 
calculations, were the mean velocity of the wind for the nine 
years, 266*9 miles; the mean amount of ozone for the same 
period, 5*07, and the mean velocity of the wind, and mean 
amount of ozone for each year. 
Year. 
Mean 
Velocity of 
the Wind 
Mean 
Observed 
Amount of 
Correction 
for Velocity 
of the 
Corrected 
Amount 
of 
1872 
in Miles. 
. 311*4 ... 
Ozone. 
... 5-60 .... 
Wind. 
.. — 0-80 ... 
Ozone. 
... 4-80 
1873 
. 296-8 ... 
... 5-40 .... 
.. — 0-54 ... 
... 4-85 
1874 
. 294-0 ... 
... 4-91 .... 
.. — 0-45 ... 
... 4-45 
1875 
. 269-2 ... 
... 4-21 .... 
.. — 0-04 ... 
... 4-17 
1876 
. 2716 ... 
... 4-51 .... 
.. — 0-08 ... 
... 4-43 
1877 
,. 286-3 ... 
... 6-01 .... 
.. — 0*41 ... 
... 5-60 
1878 
. 242-8 ... 
... 5-30 .... 
.. + 0-53 ... 
... 5-82 
1879 
. 213-8 ... 
... 4-96 .... 
.. 4 - 1-23 ... 
... 6-19 
1880 
. 2161 ... 
... 4-72 .... 
• • 1 • • • 
.. 4 - 1-11 ... 
... 5-83 
Means, . 
.... 266-9 ... 
... 5-07 ... 
... 5-13 
