THE STRUCTURE OF THE ATMOSPHERE 

 AND THE TEXTURE OF AIR CUR- 

 RENTS IN RELATION TO THE 

 PROBLEMS OF AVIATION 1 



By W. N. SHAW, F.R.S., Sc.D. 

 Director of the Meteorological Office 



In this essay it is proposed to bring under notice some of the 

 recent advances in our knowledge of air currents made in this 

 country and to consider their application to the problem of 

 navigating the air. I shall deal mainly with recent work by 

 Mr. Cave of Ditcham Park, Mr. W. H. Dines and his son 

 Mr. J. S. Dines at Pyrton Hill, Mr. Salmon at Brighton, the 

 Meteorological Department of the University of Manchester 

 and my colleagues of the Meteorological Office, Mr. Lempfert 

 and Mr. Corless. 



I suppose that when the first sailor put to sea in a boat he 

 must have thought over the phenomena of waves, tides and 

 currents so far as they could be made out from the shore. His 

 experience was very likely somewhat different from his most 

 intelligent anticipations. It is doubtful whether any amount of 

 study from the dry land would have enabled the primitive 

 navigator to deal successfully with the dangers of the deep. 

 The art of navigation must be learned afloat ; but a little experi- 

 ence combined with sufficient observations from the shore 

 might suggest some of the situations in which discretion is the 

 better part of valour. 



So it is with the airman and the atmosphere. No meteoro- 

 logist can teach an airman how to fly. Whatever may be our 

 knowledge of meteorology, the art of aerial navigation must be 

 learnt in the air ; but we can tell the airman something of the 

 details of the structure of the atmosphere which is to support 



1 The substance of two lectures delivered at the Royal Institution on May 18 

 and 25, 191 1. References to a bibliography at the end are given by numbers in 

 brackets. 



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