374 REPORTS ON THE STATE OF SCIENCE, ETC. 
transfer was effected provided for the annual publication of British Rainfall 
in the same form as in the past, and for the continuance of other work 
done by the Organization ‘in like manner.’ This agreement has been 
scrupulously observed, with the result that cordial relationships have been 
maintained with the band of voluntary observers, and with engineers and 
others who were accustomed to look to the Organization for guidance in 
questions relating to the supply and interpretation of rainfall data. 
At the time of the transfer the Organization was rightly described by 
the retiring Director, Dr. H. R. Mill, as ‘ having no parallel in any country.’ 
OUTLINE OF THE ORGANIZATION. 
In its present form the Organization forms a section of the British 
Climatology Division of the Meteorological Office, an arrangement which 
ensures that the resources of the Organization may benefit to the fullest 
extent from the large amount of rainfall data included in the climatological 
returns rendered to the Meteorological Office by voluntary and official 
stations. 'The Meteorological Office has been since 1919 attached to the 
Air Ministry, and its general policy is guided by a Committee, the 
Meteorological Committee, appointed by the Air Council, on which the 
Royal Society, the Royal Society of Edinburgh and various Government 
departments are represented. Full details will be found in the Report of 
the Meteorological Committee for 1920. 
The aim of the Organization is to encourage private persons and local 
authorities to supplement the work of paid Meteorological Office observers 
by making reliable observations of rainfall, to preserve such records for 
public use, and to publish the data as fully as possible in the annual volume 
British Rainfall. In pursuance of this object the Organization is at pains 
to get into touch with all persons who are known to possess rain-gauges 
and to invite them to forward a copy of their readings at the end of each 
year on a register (Form 1090 for inch measurements, Form 1091 for 
millimetre measurements) supplied gratis. A pamphlet, ‘ Rules for Rainfall 
Observers,’ originally drawn up by G. J. Symons, sets out the approved 
procedure for measuring rainfall and gives advice on the selection of a site 
and the type of gauge to purchase. This is sent gratis to observers, actual 
or prospective. 
The Observing Stations fall into a few well-defined categories :— 
Approximate 
Numbers 
(1) Official Meteorological Office stations—i.e. stations where 
the observers are whole-time or part-time employees of 
the Meteorological Office 4 : : : : 50 
(2) Climatological stations—i.e. stations where rainfall is 
measured as part of the routine of general climatological 
work f 2 : : : i : ; 300 
(3) Stations maintained by public authorities (mainly water 
engineers) or companies concerned with water supply or 
water power : { 4 } ; " ‘ 1,000 
(4) Stations maintained by other authorities, mainly private 
persons. : ; 4 A : i 4,000 
The observers in category (1) are paid for their observations and returns 
by the Air Ministry. In a few other cases where a voluntary observer is 
not available a small annual payment is made for observations of rainfall, 
and in a few additional cases the observer takes readings without payment 
