30 On the General Circulation of the Atmosphere. 



atmosphere, nor with those more recently obtained by Bigelow, because 

 the method of treatment is in some respects novel and it seems 

 desirable to wait for its further application before making any such 

 comparison. I may remark, however, with regard to the theories of 

 the two authors first mentioned, that a steady circulation round the 

 polar regions requires only the supply of the comparatively small 

 amount of energy necessary to make up the loss occasioned by surface 

 friction, and consequently no great transference of energy from the 

 equatorial regions to middle or higher latitudes in the form of heat or 

 otherwise is demanded for the maintenance of the circulation. 



Moreover, I have confined my observations to the barometric 

 distributions for the month of January. So far as I have examined 

 the distributions for July, the conclusions to be drawn from them are 

 in many respects similar, but the separation of the pressure component 

 for easterly circulation from that for westerly is not complete at the 

 4000 metre level as it is in the case of January. 



In conclusion, I desire to acknowledge the assistance I have received 

 from Mr. G. T. Bennett, M.A., of Emmanuel College, Cambridge, with 

 whom I have discussed especially the dynamical questions involved, 

 and from Mr. K. G. K. Lempfert, M.A., and other members of the 

 staff of the Meteorological Office, who have supplied me with much of 

 the material upon which the general conclusions set out in this paper 

 have been based. 



