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ON THE YAEIATION OF THE HOURLY METEORO- 

 LOGICAL NORMALS AT KIMBERLEY DURING THE 

 PASSAGE OF A BAROMETRIC DEPRESSION. 



By J. R. Sutton, M.A., F.R.Met.S. 



(With 2 Charts.) 



(Read May 31, 1905.) 



The present paper is the result of an attempt (1) to determine the 

 variation of the hourly normals of the more important meteorological 

 elements introduced by the passage of a barometric depression over 

 Kimberley ; and (2), incidentally, to learn something of the conditions 

 prevailing in the depression itself. 



In the absence of synoptic charts, any information under the 

 second head can, of course, only be small in quantity. And I have 

 no means of making it more definite because, for some reason, the 

 Meteorological Commission has steadily, and at all times, refused to 

 allow me to inspect any of their numerous records for this or any 

 other purpose. 



The information obtained under the first head is to be regarded as 

 preliminary to a more extended treatment later on, and as indicating 

 the direction of future research. 



The ordinary depression may last for any time from a day to a 

 week, and the winds generated may blow with any velocity from 

 5 to 35 miles an hour — and perhaps up to 50 miles an hour in 

 occasional gusts. When they first become noticeable to all by 

 reason of the strength of the wind, they set in with warm, discom- 

 forting gusts from the north or north-west, and pass away with 

 cool, steady winds from south-west or south. They often bring 

 light showers, but not often heavy rain. Frequently the approach of 

 the centre, or trough, is heralded by clouds of dust ; but it is remark- 

 able that equally strong winds in the rear of the centre seldom raise 

 any dust to speak of. 



For the purposes of the present discussion, 105 separate depres- 



