METEOROLOGY. 377 



METEOROLOGY. 



Bjerknes, V., University of Leipzig, Leipzig, Germany. Preparation of a 

 work on the application of the methods of hydrodynamics and thermodynamics 

 to practical meteorology and hydrography. (For previous reports see Year 

 Books Nos. 5-13.) 



The preparatory investigations for the third volume of "Dynamic 

 Meteorology and Hydrography" have been continued. A complete 

 account of the results obtained hitherto relating to the influence of 

 friction upon atmospheric motions has been pubUshed by Messrs. 

 Hesselberg and Sverdrup. Indirect results of these investigations on 

 friction are marked by Hesselberg's papers ''Ueber die Beziehung 

 zwischen Luftdruck und Wind im nichtstationaren Fall," "Ueber eine 

 Beziehung zwischen Druckgradient, Wind und Gradientenanderung" 

 and that of Hesselberg and Sverdrup '' Windanderung mit der Hohe vom 

 Erdboden bis etwa 3000 m Hohe" (Beitr. z. Ph. d. fr. Atm., in print). 

 A subject of great practical importance has been treated in a paper of 

 Hesselberg and Friedmann "Die Grossenordnung der meteorologischen 

 Elemente und ihrer raumhchen und zeitlichen Ableitungen." The 

 results contained in this paper have proved to be of great use for our 

 further work. 



Another new subject which has been taken up is that of internal 

 atmospheric wave-motions. The principal mathematical problems 

 forming the base of these investigations have been solved and a pre- 

 liminary conomunication concerning the results has been given in the 

 paper of V. Bjerknes "Theoretisch meteorologische Mitteilungen" 

 (Met. Zeitschrift, in print). These investigations on wave-motions 

 will form the introduction to further ones concerning the important 

 subject of the stability of cyclones and anticyclones. 



