288 JF. Waldo — Contributions to Dynamical Meteorology. 



the most practical ideas of the paper, and the author calls atten- 

 tion to several points that will receive the consideration of 

 even the non-mathematical meteorologist. The manner in 

 which the air is gradually warmed up by convection is briefly 

 described, and the effects of a warm layer above (as well as 

 below) are pointed out. The modifying effects of friction 

 where layers of different velocities are mixed are examined ; 

 and many of the observed facts connected with the general 

 circulation are briefly accounted for. Special attention is also 

 called to the application of the theory of discontinuous fluid 

 motion which was elaborated by the author in the paper pre- 

 sented to the Berlin Academy in 1868. The importance of 

 the application of these ideas to meteorology has been repeat- 

 edly pointed out by several meteorologists, but the advice has 

 been little heeded because it is so difficult a question to 

 handle. The author promises a further treatment of the sub- 

 ject, which will be eagerly watched for, 



No. 10. — This is by far the most elaborate contribution Mr. 

 Moller has made to meteorological science, and as it is the 

 result of seven or eight years of study of the questions consid- 

 ered, it deserves a careful reading. The following headings of 

 sections show the great number of special topics treated : In- 

 troduction (in which he shows the difficulties in the way of the 

 satisfactory application of general theories like Ferrel's) ; 1. 

 The deviatory force of the earth's rotation ; 2. The surfaces of 

 equal*pressure, and the horizontal differences of temperature ; 

 3. The location of the surfaces of equal pressure in the earth's 

 atmosphere ; 4. Ferrel's explanation of the cause of a main- 

 tenance of steep inclination of surfaces of equal pressure in 

 the temperate and cold zones of the earth's atmosphere; 5. 

 Ferrel's computations ; 6. The performance of the work pro- 

 duced by the differences of temperature in the atmosphere ; 7. 

 The facts concerning the existing air circulation ; a. The air 

 circulation of the hot zone in general ; b. Representation of 

 the air circulation in the hot zone, based on numerical calcula- 

 tions ; c. The belt of the higher pressure ; d. The air circu- 

 lation in the temperate zone for the year, also in the Arctic 

 zone in summer ; e. Phenomena of changing motions in the 

 atmosphere ; f. The calm zones at the equator ; g. The Arc- 

 tic zone in winter ; h. The amount of work performed in 

 different upper air layers ; i. Combination of the results, 8. 

 Closing remarks. Illustrations. A postscript of three pages 

 contains some items omitted from the main paper and also 

 some remarks on Ferrel's and Oberbeck's recent works. 



While most of the papers by the writers mentioned in this 

 review have been analytical in character, the present one is 

 synthetical, and the author has necessarily been obliged to give 



