The Spring Drought o/1893. 
349 
present year 1893 I have seen many assertions as to absolutely 
rainless periods which are inaccurate. Or, to go back to Feb- 
ruary 1891, the man without a rain gauge, and the careless 
man with one, would each report “ a rainless month,” while the 
careful observer would have on one or two occasions just enough 
to give him a measurement of - 01 inch, and therefore he would 
not have the remarkable record. In fact, the more careful the 
observer the fewer the wonderful droughts that he will be able 
to report. I have no doubt whatever that early records of 
droughts must for this reason be received with caution, and, as 
I have already given a list of them from A.D. 298 to 188/ in 
British Rainfall , 1887, I think that I had better not reopen the 
question, but confine my attention to the present century, and 
to actual quantitative measures which are practically if not 
absolutely accurate. 
As I have already stated, no two droughts are identical, and 
before any useful comparison can be made, some agreement 
must be arrived at concerning their classification. When 
dealing with the subject in 1887 I made two proposals which 
have never been challenged, and which may, I think, be regarded 
as being generally approved by British meteorologists. The 
following are the definitions : — 
Absolute Droughts. Periods of more than 14 consecutive 
days without measurable rain. 
Partial Droughts. Periods of more than 28 consecutive 
days, the aggregate rainfall of which does not exceed 0 01 inch 
per diem. 
Any accuratelg leapt record of rainfall will supply the data 
for making strictly comparable lists of the occurrence of each 
class of droughts. The “ absolute ” droughts can be taken out 
very easily ; but the extraction of “ partial ” droughts requires 
care, as they can often be shifted a few days earlier or later by 
taking in small daily amounts at one end or the other. 
I have had the droughts of each class taken out for several 
stations in and near London so as to cover the whole of the 
present century, and 1 have given the values in extenso in the 
preceding tables. 
The position of the several stations is shown by the map on 
p. 350. 
These tables supply a mass of information which it would 
take months to consider thoroughly. We have recently passed 
through a long, but (except perhaps locally) by no means unpre- 
cedented spring drought. I think, however, that before dealing 
with the drought of 1893 it will be well to refer to those spring 
droughts which most nearly resemble it, 
