/\ W'itLlo — Contributions to Dynamical Meteorology* 285 



by the author. He finds, for example, that "if two cyclones 

 are formed in the atmosphere they will mutually approach cadi 

 other, since they rotate in a cycional direction about a definite 

 point at rest; while two anti-cyclones on the contrary separate, 

 ae they rotate in an anti-cyclonal direction about a definite 

 point. In the last chapter are numerous conclusions that will 

 be of great value if they can be found to hold good in the act- 

 ual conditions o\' the atmosphere. (I hope to give an extended 

 review <>{ this whole memoir when I can secure a copy of the 

 first portion. — F. W.). 



. C. — T r A. Oberbeck has rendered important ser- 



vice to several branches of physics. His papers on electricity, 

 liuid motion (and other conditions of fluids), and atmospheric 

 mechanics, are all in the front rank of such investigations, in 

 L882, Prof. Oberbeck published a very important paper in 

 Wiedmann'8 Annalen with the title, k * ueber die Bewegungen 

 der Luft an der Erdoberflache," but I think lie had not pub 

 lished any other important paper on meteorology until the 

 present contribution appeared ; the author, in the meantime. 

 having gone from the university of Halle to that at Griefs- 

 wald. 



In the present paper the author refers to the progress that 

 has been made in the study of atmospheric mechanics during 

 the past ten years, and remarks that although some special 

 points have been satisfactorily treated, as is shown by the 

 excellent resume given in the Lehrbuch der Meteorologie, 

 written by Dr. A. Sprung, yet no complete theory can be 

 deduced until we have a better knowledge of the upper air 

 currents. He says, however, that " The outlines of a rational 

 mechanics of the atmosphere are given in the paper of 

 W. Siemens, " Die Erhaltung der Krafte in Luftmeere der 

 Erde," (which is No. 1, of the memoirs we are now con- 

 sidering), and thinks it would be well to give a further 

 mathematical development of the theory outlined in that 

 brief paper. On account of the great difficulties to be 

 encountered in any general solution of the problem with 

 all the secondary phenomena, the author limits himself to 

 the computation of the air currents, to the exclusion of such 

 questions as " pressure," distribution, etc. A statement is then 

 made of the various causes of atmospheric motions: tempera- 

 ture, influence of the earth's rotation, friction. Concerning 

 this Last, he Bays that the theories that have heretofore taken 

 into account the friction have not been properly constructed, 

 and that according to his view the law of friction for atmos- 

 pheric currents is the same as has been developed for fluid 

 motions, hut the laboratory numerical coefficients cannot be 

 applied without great modification, according to the different 



