INLAND WATER SURVEY 383 
(2) Advice by the British Rainfall Organization in association with the 
Instruments Division of the Meteorological Office, in regard to 
instruments, including evaporation gauges and percolation gauges. 
(3) The selection by the British Rainfall Organization of stations whose 
records should be used for routine evaluations of general rainfall. 
(4) Co-operation with the British. Rainfall Organization in obtaining 
additional observers where necessary. 
(5) Avoidance of overlapping in regard to publication of rainfall data. 
In regard to (5) it may be pertinent to point out that twenty years ago 
there were, in the British Isles, four separate bodies concerned in collecting 
and publishing meteorological data, viz. :— 
The Meteorological Office. 
The British Rainfall Organization. 
The Royal Meteorological Society. 
The Scottish Meteorological Society. 
There is now only one such body, the Meteorological Office, of which 
the British Rainfall Organization forms a constituent part. This unification 
of control has taken years to achieve, and has proved advantageous to all 
concerned. Any arrangement made for the supply of rainfall data to the 
Water. Survey Organisation should be such as to comply with the general 
principle of unification. It should not prove difficult to formulate a scheme 
under which the British Rainfall Organization maintained general super- 
vision of the rainfall data, so that reports rendered by voluntary observers 
remained reports to the British Rainfall Organization, although the scheme 
might involve their passing through the hands of Water Survey officers at 
some stage. 
Such are the general principles which should, I suggest, be kept in 
mind when framing an actual scheme for Inland Water Survey on a national 
scale. 
Main Memoranpum D. 
SURFACE WATER. 
By W. N. McC.ean. 
1. MEASUREMENTS AND RECORDS IN OTHER COUNTRIES. 
In many other countries measurements and records of river flow appear 
to be better organised than similar work in the British Isles. Probably this 
is due to the particular problems to be solved and to the lack of rainfall 
records, such as those of the British Rainfall Organization. 
‘The existing organisation of Inland Water Survey in other countries is 
dealt with in Memorandum B. 
2. MEASUREMENT AND RECORDS IN THE BRITISH ISLES. 
All over the country a great many surface water measurements have 
been made, and in many cases there are long records of flow, or of water 
levels. Almost all of these measurements and records arise out of com- 
mercial developments of water and, as is only natural, the measurements 
made have been such as each development required. The measurements 
of a water supply authority are generally those of the actual supply, and of 
the water required by law to pass down the stream or river; and there are 
usually no measurements of total run-off from an area. 
