
British Rainfall 1867 page 18
is at the head of Langdale, nearly in the bottom of the
valley; No.23 at the foot of Loughrigg, near Elterwater; and
No.24 on the top of Loughrigg, threequarters of a mile
E.N.E. of No.23.
Lastly, there are, and have been, at intervals, a large
number of gauges at the principal residences in the
district. Except, therefore, that there are still some blank
spaces too large for so important a locality, we may
congratulate ourselves on having infinitely better data than
has ever been the case before. Thanks to the liberal help of
Mr. Fletcher, and one or two other friends, I hope to keep
these new gauges at work for a few years more; but, in the
interim, it is of high interest to see the results already
ascertained  and which I would dedicate to one (need I say
it was not Mr. Fletcher?) who told me that he and Dr. Miller
had found out all there was to find. Indeed! I wish he would
tell me (before reading the rest of this article) the mean
fall on Matterdale Common, at the head of Hawsewater, or in
Sleddale, within 20 inches of the truth.
APPROXIMATE DETERMINATION OF THE MEAN ANNUAL FALL AT VARIOUS
STATIONS IN THE LAKE DISTRICT.
As years roll on, and the laws and distribution of rain are
gradually developed, the fallacy of practices of the wisest
of our precursors is rendered evident to all. Without
quoting such preposterous cases as that of tabulating the
fall in one year as the mean rainfall of the place of
observation, in which case an error of 50 per cent. may
occur,* many have thought that five or six years
would give a pretty fair mean, especially if two or three
stations were taken together. The following table shows that
the six years, 1853 to 1858, were more than 20 per cent.
below the average of 22 years, and that the five years,
18591863, were nearly 20 per cent. above it. Thus we have
two periods of six, and five years respectively, in one of
which the fall is half as large again as in the other. Thus
it becomes obvious that the mean fall can be ascertained
only by two methods: either by longcontinued observation at
the place, or by reference to some proximate
longestablished gauge. This is the only method by which the
observations made in the Lake district can be reduced to
their true values. Most fortunately, the registers at The
Howe, Troutbeck, at Seathwaite, and at Keswick, extend from
the first year of Dr. Miller's work to the present time;
they have therefore been employed as standards of reference
for all the gauges, Dr. Miller's, Mr. Fletcher's, and my
own:
* For example, the fall at Troutbeck, in 1861, was
116 in., and in 1885 it was 47 1/2 in.; in either case it
would have been more than 30 in. in error.
