24 VEGETATION OF THE PEAK DISTRICT [CH. 
finished vegetation maps of different parts of Great Britain, 
such as the Isle of Wight, Hampshire, the Cleveland District 
of Yorkshire, and Lanarkshire; and these maps cannot at 
present be published owing to lack of funds. The time seems 
to be approaching, therefore, for placing a vegetation survey 
of this country on the same official basis as the existing 
geological survey. 
RAINFALL! 
There are not enough rainfall stations in the district, 
especially in the moorland region, with sufficiently long and 
continuous records to justify the construction of a map showing 
rainfall lines. Dr H. R. Mill, however, has kindly supplied the 
following statistics giving yearly and monthly averages for 
thirty years at ten stations distributed as regularly as possible 
over the area covered by the vegetation maps. The figures 
given on the following page represent the average rainfall to 
the nearest inch, during the thirty years 1870—1899. The 
particular rainfall stations have been selected by reason of the 
fact that they possess long and accurate records; and the yearly 
figures may be taken as satisfactory for the stations in question. 
A slightly greater rainfall may be safely assumed to occur on 
the higher grounds and on the leeward side of the highest hills. 
The figures showing the monthly averages may be taken as 
fairly satisfactory; but experience shows that for monthly 
rainfall figures to be fully satisfactory, fifty years or more are 
required, because a rainfall equal to the monthly average may 
occur in a single day, and because, on the other hand, a month 
may have no rainfall at all. The monthly rainfall of Burton- 
on-Trent (see the left-hand column) is added in order to furnish 
a comparison with a neighbouring town situated at a low 
altitude. 
It will be seen from the figures in the table which follows 
that the first five months of the year are the driest, and that 
the driest of all is April, in spite of a popular opinion to the 
contrary. The soil, however, is often very wet during these 
months, owing to low evaporation. Of the remaining seven 
wet months, October is, in this district, by far the wettest. 
1 This section has been kindly revised by Dr H. R. Mill, the Director of the 
British Rainfall Organization, and Editor of British Rainfall. 
