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XVIII. 
REPORT ON THE RAINFALL IN HERTFORDSHIRE IN THE 
YEAR 1901 . 
By John Hopkinson, E.L.S., E.GKS., E.R.Met.Soc., Assoc.Inst.C.E. 
The alterations in our staff of observers for the year 1901 are 
less numerous than they were in the previous year, when there 
were sis losses and five gains, the losses for last year being three 
and the gains four, giving an increase of one. No return has 
been received from the Union Workhouse, Royston, and two rainfall 
stations have been discontinued—The Limes, Northchurch, owing 
to the removal of the observer, Mr. Sutton; and Marden Hill, 
Tewin, owing to the death of the observer, Mr. Richard Hoare. 
The gains are The Chilterns, Hitchin; Danesbury, Welwyn; 
Hamels Park, Buntingford, a former station reinstated; and the 
Sewage Works, Hertford, for which we are indebted to the Engineer 
of the East London Waterworks. Danesbury, Welwyn, takes the 
place of Marden Hill, Tewin, leaving the number of stations in 
the Mimram river-basin the same as before ; but each of the other 
alterations makes a difference in the number of gauges in the 
river-basin in which it has taken place. 
These alterations result in the principal table containing the 
records of 45 stations, being the same number as in the year 1899. 
The number of perfect daily records received is 35. This has only 
once been exceeded, in 1898, when the number was 36. 
Particulars of the 45 rainfall stations, and the monthly and 
total rainfall and number of days of rain in 1901, are given in 
Tables I and II, pp. 157-159. 
A supplementary table (Table III, p. 160) gives ten other 
records of the total rainfall in the year. Two are records of 
additional gauges at Rothamsted, one is that of an additional gauge 
at Odsey, one is the return from Chipperfield omitted from the 
principal table for the same reason as in the previous year, and 
six are from ‘British Rainfall, 1901.’ 
The mean rainfall in Hertfordshire in the year 1901 was 21-12 
inches. This is 3-66 ins. below the average for the decade 1890-99, 
and 5*03 ins. below that for the 60 years 1840-99. The year was 
therefore one of small rainfall. The mean number of wet days in 
the year was 138, being 29 less than the average for the thirty 
years 1870-99, and 39 less than that for the previous year. The 
frequency of the rain was much less in proportion to the average 
than was the amount. 
Droughts in 1901.—There was only one “absolute drought” 
(a period of more than 14 days without a measurable quantity of 
rain) and one “partial drought” (a period of more than 28 days 
with an average fall of less than 0-01 inch of rain per diem). The 
absolute drought was in May, and lasted for 15 days, May 10-24, 
