run-off. However, the main dikes held in the centre of the city of Winnipeg, where more than 3,000,000 bags for sand had been hauled into the area, mostly by air. For two weeks the river gauges recorded approximately 12 f t above flood-level, but by 24 May the river had fallen almost a foot from the crest- level, and the gradual recession continued.

As the waters receded, governmental authorities and engineers considered methods of preventing the recurrence of such a disaster, which had caused damage estimated aa high aa $lO0,000,OOO. The cost of a permanent diking system appeared prohibitive, and such a project might well prove an engineering impossibility in the flat Red River plain.

(1) CANADA 1949

(2) FOSTER, EDQAR E. 1948

(3) UNITED STATES 1949-1950

(4) KLEIN, WILLIAM H. 1950 (5) KLEIN, WILLIAM H. 1950

(6) CANADA 1950

REFERENCES Water Resources Paper, No. 97, p. 71 ; I)ominion Water and Power Bureau, Department of Mines and Resources. King’s Printer, Ottawa. Rainfdl and Run-off, pp. 343-352. New York

Fargo, N.D., Station. Meteurological Summury ; WS USWB, Department of

Wwtherwise Vol. 3, No. 2 ; pp. 38-39. Philadelphia. Monthly Weather Review. Vol. 78, No. 1 ; pp.

13-14 ; Department of Commerce, Washington. Unpublished &to ; Water Resources Division,

Department of Resources and Development, Winnipeg.

(The MacMillan Company).

Forms 1030 and lOOlC ; Commerce, Kansas City.

FIFTY YEARS OF BRITISH WEATHER By R. B. M. LEVICK

If correspondence received has accurately reflected readers’ opinions , my article Fifty years of Englkh Weather ” in July 1949 waa greeted with a g d deal of scepticism, which I can appreciate is only natural in the circumstances. Apparent fluctuations due to inconsistency in. classification, it was felt, are likely to be so large that they would obscure the real fluctuations in frequency of type. I would like to say, therefore, that I have throughout exercised such cam in classification (the more doubtful the type, the greater the care), and the distinction between the types is so clear in my own mind, that I am quite sure this is not the case.

To convince the reader entirely, it would of course be desirable to repeat the observations without referring to previous results, and to show that the second set of results was practically identical with the first. This, unfor- tunately, would take more time than I am able to spare ; if, however, the reader will ghnce at the diagrams for Scotland and Ireland (see Fig. 2), he will notice a certain similarity in the frequency of particular types on parti- cular years. (I would point out here that the Scottish and Irish observations were taken independently, never on the same day for a particular period, and

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I was carcfirl not to refer to previous results when classifying). It will surely be agreed that this similarity must be a fair reflection of the true similarity to be expected from the proximity of Scotland and Ireland. I think the most sceptical of readers will agree that this indicates that the classification is in fact sufficiently consistent to make the deduced seasonal variations in frequency (see Pig. 1) significant. These latter diagram8 are really the most interest

Vig. 1. l’ercmlttlgc. fwquoncy of the various weather-types in Scotlantl and Ircland showing tlcpnrtnrc from ;~vcw~g:’ in (*act1 ( ‘ t w for the period 1898-1947

iiig, since positive conclusions can be derived from them. The conclusioils for Scotland and Ireland arc identical with those given for England 011

p. 210 of Weather (July 1949), with the following exceptions :- March Easterly type not the maximum though well above average. A y i l Easterly type just above instead of well above average. September Anticyclonic type not as frequent as in June. October No pronounced maximum of easterly type.

‘The differences are cvicleiitly quite trivial, and the general weather expectations are the sanie. I r i o n t h by 11ionf.h. in Scotland and Irela,nd as in England.

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The classification of types for Scotland and Ireland waa almost identical with the system for England, with " Scotland " or '' Ireland " substituted for " Britain ". At the same time, it must be borne in mind that the tem- perature and humidity associated with each type depend upon the locality

SCOTLAND

ANTICYCLONIC IRELAND

SCOTLAND

IRELANO

SCOTLAND

IRELAND - NORTHfRLY CYCLONIC

Fig. 2. Comparison of the percentage frrquenciex of thevsrious weather-types of Scotland and Ireelend, 1898-1947. Vertical scales reed upward for Scotland but downward for Irahd

88 well aa the season. For instance, in winter the westerly, north-westerly and northerly-oyclonic types are colder in Scotland than in England, while the easterly type is often less cold due to the warming of intensely cold con- t ~ e n t a l air during its passage across the North Sea. Also the easterly type in Ireland is drier, and the westerly type wetter, than in England.

SITUATION WANTED Ex-Senior Asst. &I&. OfHcer requires an intemthg post in Meteorology or one of the

natural sciences, preferably research work, where initiative and enthusiasm can be of use. Box No. 66, Weather, 49 Cromwell Road, London, S.W.7.

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