March 6, 1919] 



NATURE 



countries for a while, but this was soon rectified, and 

 daily weather reports could again be prepared, though 

 lacking part of the Continental information. As time 

 went on the need for more and more distant stations 

 was felt, and by igi6 reports were being regularly 

 received from Spitsbergen to the North African coast 

 and Cairo, and from Iceland and the Azores to the 

 Russian stations of Petrograd, Nicholaieff, Sebastc^ol, 

 and Batum. 



ITie supply of daily weather reports and forecasts to 

 the public was stopped, but their preparation was 

 continued actively in the Meteorological Office, where 

 ihe telegraphic reports which were collected several 

 times daily reached the number of about one hundred, 

 and the information which they contained was com- 

 piled on working charts from which the forecasts were 

 prepared. These were issued to the Admiralty, to 

 various dockyards, to the Grand Fleet, various battle 

 squadrons, submarine flotillas, etc., each of which 

 required reports and forecasts adapted to their special 

 needs. Similarly information was supplied to the 

 Naval Meteorological Service for the Royal Naval Air 

 Service, and to numerous units of the Royal Flying 

 Corps, or the Royal Air Force as it afterwards became. 



To provide information for aviators in the early 

 morning or for use in preparing plans for the day's 

 operations, it became necessary to take observations 

 in the early hours of the morning, and 3 a.m. was 

 the hour chosen at first, but this was not found to be 

 early enough, and i a.m. was finally adopted, making 

 the observing hours i a.m., 7 a.m., i p.m., and 6 p.m. 

 Thus a continuous twenty-four-hour forecasting service 

 was established, and has been maintained in operation 

 up to the present time, to prepare forecasts and reports 

 four times daily ; and to telegraph the observations 

 taken at selected stations to the Meteorological Section 

 at the British General Headquarters in France, and 

 ro other stations that required them, as well as to the 

 Meteorological Service of the French Army, and later 

 to that of the American Expeditionary Force. 



Under service conditions something simpler, plainer, 

 and more direct in its presentation of the opinions of 

 the trained meteorologist who prepared it than the 

 ordinary daily weather report with its statistical data 

 was needed. Those who had to make use of the daily 

 weather reports were usually far too busy to wish to 

 study the statistical material before accepting the 

 meteorological opinions which were off'ered to them. 

 They wanted a direct statement of expert opinion 

 which they could make use of in preparing their own 

 plans of action. The desire for such expert assistance 

 was also shown by many requests that forecasts should 

 be expressed in "perfectly simple and non-technical 

 ' inguage." To this very reasonable request it isnot 



' easy to accede as it may seem. Such expressions 

 - "a depression advancing from the westward," "a 



condary depression developing over the Channel," 



an anticyclone spreading northward," are more than 

 mere statements of fact; they convey to all who arc 

 acquainted with meteorology much additional informa- 

 tion depending on the weather conditions described, 

 wliich it would take several paragraphs to state 

 simply and in non-technical language. 



So far as meteorological conditions could be set out 

 in plain language, this was done in these special daily 

 weather reports, which were issued in the early morn- 

 ing, before noon, and in the afternoon to all who 

 required them ; and these were supplemented by 

 special summaries, one of which dealt with the pre- 

 vailing and the prospective weather conditions on all 

 fronts where military operations were in progress, and 

 another with the weather conditions in the various 

 sea areas round Europe. 



The whole of this information was of a highly con- 

 fidential character, since Germany and .Austria were 

 NO. 2575, VOL. 103] 



cut off from all weather reports from meteorological 

 stations to the westward, except those of neutral 

 countries, Norway and Spain. 



We shall doubtless learn eventually to what extent 

 the precautions taken sufficed to prevent information 

 about the weather conditions over the British Isles 

 and to the westward reaching the Central Ennpires, 

 but at the time we had to depend mainly on negative 

 evidence. It was not difficult to estimate from the 

 working weather-chart what sort of forecast the enemv 

 meteorologists would probably make on the assumption 

 that the information from a wide area to the west- 

 ward of them was not available, and this was done 

 daily as part of the routine of the Meteorological 

 Office. ^ In the case of attacks by enemy aircraft it 

 was fair to assume that his meteorological service 

 considered the conditions to be reasonably favour- 

 able; and this was compared with the estimate of 

 his opinion which had been formed here. Occa- 

 sionally enemy forecasts were available, and these 

 were compared in the same way. Negative evidence 

 is not conclusive, but the impression that we gained 

 was that little, if any, meteorological information of 

 value was obtained from our area. 



Many cases could be cited where operations were 

 undertaken by the enemy which it seemed ver\' un- 

 likely that he would have' undertaken had he possessed 

 the information which we had here. 



By the spring of 1915 two branches of the Armv, 

 the Royal Flymg Corps and the Special Brigade, 

 R.E. (Chemical Warfare), had deaded that they 

 required the co-operation of trained meteorologists 

 who could explain the meaning and the limits of the 

 forecast, answer questions or give advice, and arrange 

 for fuller or more suitable information being furnished 

 when required. 



These demands for the provision of trained meteoro- 

 logists in France led to the formation of a meteoro- 

 logical section as a unit of the Corps of Royal 

 Engineers which had at first a strength of about four 

 officers and twenty non-commissioned officers, but the 

 establishment was repeated'y increased until, when 

 hostilities ceased, it consisted of thirty-two officers and 

 about two hundred other ranks, and provided sections 

 for duty, not only in France, but also on the Italian 

 and Macedonian fronts, besides a reserve section at 

 home. From a small unit at General Headquarters 

 in France the organisation developed until there was 

 a meteorological unit with each army and one with 

 the Independent Force, R.A.F., these units having 

 their groups of observers and pilot-balloon stations 

 reporting to them. The telegraphic weather reports 

 from the stations in the British Isles, as well as those 

 received from a large number of European stations, 

 were at first thrice daily, and later four times daily, 

 telegraphed from the Meteorological Office in London 

 to the Meteorological Section at General Headquarters 

 in France, in order that weather-maps might be drawn 

 and forecasts prepared there as might be required. 

 This information was supplemented by data which the 

 Meteorological Section collected from its station on 

 the British front, and also from other parts of France 

 through the French Meteorological Services. 



In this way on the Western front, and similarly 

 at; later dates on the Italian and Macedonian fronts, 

 a network of meteorological stations was built up, 

 which, with the addition of the data and reports fur- 

 nished by the Meteorological Office, enabled the 

 meteorological officers to supply the information which 

 the different Services required for their special pur- 

 poses, to issue forecasts and weather warnings, and 

 also, as will be seen later, to increase very material!} 

 the accuracy of the work of some of the Services. 



The task of providing the personnel for this military 

 unit was no easy one, for, as has been already men- 



