eR 
255 
The mean yearly rain-fall at Bath, determined by the results 
given in the above Table, is 29.986 inches. Allowing for errors, it 
might probably be set at 30 inches at least if not more. 
The wettest year in the decade was 1872, when the fall 
amounted to 37.568 inches. The driest year was 1870, when the 
fall was only 20.982 inches, the difference between the two falls 
amounting to 16.586 inches. These two extremes afford an 
illustration of what was remarked above as to how an average is 
affected by the occurrence of either of such extremes in a decade. 
If, in calculating the mean rain-fall at Bath from Table I., we 
omit the exceptionally dry year of 1870, the mean is found to be 
30.987 inches, or an inch more than the mean obtained from the 
whole ten years. If on the other hand we omit the exceptionally 
wet year of 1872, the mean is found to be 29.144 inches, or 
between e‘¢ht and nine tenths of an inch Jess than the mean of 
the whole ten years. 
The next wettest year, after 1872, was 1866—when the fall 
amounted to 35.878 inches. The next driest, after 1870, was 
1873—when the fall was reduced to 24.890 inches. The year 
approaching nearest to the mean was 1868, only varying from it 
by .035 inches. 
From estimating the mean yearly rain-fall at Bath, we may pass 
to that of each of the seasons, as well as that of the several 
months relatively considered. The former is as follows :— 
Mean Spring Rain-fall 5.492 inches. 
Mean Summer Ditto 6.227 
Mean Autumn Ditto 8.892 
Mean Winter Ditto 9.370 ,, 
From this it appears that the rain-fall is least in spring, the fall 
increasing in summer, with a further increase in autumn, au 
greatest in winter. 
With regard to the several months the mean monthly fall is 
greatest in January. This month was absolutely the wettest in 
four years out of the ten, viz., in 1867, 1869, 1872 and 1873- 
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