10 " ............... 1.25 1.50 2.00 -- --
15 " ............... 1.05 1.25 1.50 -- --
20 " ............... 0.95 1.05 1.30 1.20 3.00
25 " ............... 0.85 0.95 1.15 -- --
30 " ............... 0.80 0.90 1.05 1.00 2.50
35 " ............... 0.75 0.85 0.95 -- --
40 " ............... 0.70 0.80 0.90 -- --
45 " ............... 0.65 0.75 0.85 -- --
1 hour .................. 0.50 0.60 0.70 0.75 1.80
1-1/2 " .................. 0.40 0.50 0.60 -- 1.40
2 " .................. 0.30 0.40 0.50 0.50 1.10


The figures in column A will not probably be exceeded more than
once in each year, those in column B will not probably be
exceeded more than once in three years, while those in column C
will rarely be exceeded at all. Columns D and E refer to the
records tabulated by the Meteorological Office, the rainfall
given in column D being described in their publication as
"falls too numerous to require insertion," and those in column
E as "extreme falls rarely exceeded." It must, however, be
borne in mind that the Meteorological Office figures relate to
records derived from all parts of the country, and although the
falls mentioned may occur at several towns in any one year it
may be many years before the same towns are again visited by
storms of equal magnitude.

While it is convenient to consider the quantity of rainfall for
which provision is to be made in terms of the rate of fall in
inches per hour, it will be useful for the practical