ON THE RAINFALL IN THE BRITISH ISLES. 441 
those where it is large the minimum is in May. The deficit of two or three 
days in February should be allowed for, and we shall then find the true mi- 
nimum is usually in March, especially as that month contains thirty-one days. 
One more feature is to be noticed ; for it is impossible in the limited space 
which is here available to do more than point out the principal peculiarities 
in so large a work. It is this:—at stations where the annual rainfall is 
large, the maximum monthly fall is a more decided maximum, and the mi- 
nimum a more decided minimum than at stations where the amount is small— 
in fact the greater the total yearly fall the greater the monthly range. 
The above statements will be rendered more clear by the following dia- 
gram (fig. 4), in which the curves for the 20 to 25-in. and 70 to 75-in. 
groups for the period 1850-59 are shown. This particular period is chosen 
because the larger number of returns give more satisfactorily the variations 
which, however, are clearly discernible in all the periods yet examined. 
Fig. 4. Exeranp anp Watts. (Western District.) 
JEMAMITTAS O E MAD 
(N.B. The 70 to 75-in. curve has been chosen in preference to the (ex- 
ceptional) 125 to 130-in., as it is obtained from more than one station, 
and may be better compared with other returns.) 
The first six months of the year are repeated after December, in order that 
the complete curve for all parts of the year may be seen more readily. 
Scotland.—In considering the registers from the Scotch stations (Table 
Ila.), we are obliged to speak with some reserve, as the number of reports 
received from that country for the period under discussion is very small. 
During 1830-39, the first three groups are represented only in the eastern, 
and the last three only in the western districts. 
In those cases alone where the number of reports is insufficient to furnish 
reliable mean values, is a summer maximum shown at all; the tendency is 
to an autumnal excess at stations with small annual falls. The winter 
maximum at wet stations is, however, very decided. In the following diagram 
(fig. 5) the “20 to 25-in.” curve for the eastern district, and the “70 
to 75-in.” curve for the western (1850-59) are shown. Although the latter is 
obtained from but one station, it agrees so well with the other higher groups, 
that it may be presumed to represent very approximately the true average. 
1868. 24 
