PHYSICS OF THE GLOBE. 73 



gradient than the south and west winds in order to acquire 

 the same velocity. The law ordinarily called Buys-Ballot's 

 was first demonstrated in 1853 by J. W. Coffin, and was ex- 

 pressed substantially as follows : The winds are inclined at 

 an angle of 65 to the direction of the lowest pressure. 



C. de Seul contributes to meteorology, as his magister dis- 

 sertation, the results of most laborious toil, viz., the monthly, 

 seasonal, and annual wind-roses for six stations in Southern 

 Norway, and for the six climatic elements, viz., pressure, 

 temperature, absolute and relative humidity, cloudiness, and 

 wind-force. The scientific value of the work is highly spo- 

 ken of by Moh n. 



In Brault's " Circulation Amospherique de l'Atlantique 

 Nord" a work of great labor, and apparently a worthy con- 

 tinuation of those studies that were begun by Maury, and to 

 which Buys-Ballot, Buchan, Hoffnieyer, Brito de Capello, Cor- 

 nelissen, and Scott have of late years made so many contribu- 

 tions Brault has taken an important step in that he has un- 

 dertaken to classify his 200,000 observations of the wind ac- 

 cording to the force as well as according to the direction. 

 Besides the excellent charts and the ninety pages giving in 

 detail the data on which the charts are based, the author 

 gives an interesting sketch of the actual state of the works 

 in nautical meteorology that were begun in 18G9 under the 

 administration of Admiral De Genouilly, whence it appears 

 that from the journals kept by French vessels the French 

 Hydrographic Office has compiled a large number of charts 

 and tables, which will, it is hoped, soon be published. A 

 glowing tribute is paid by him to the importance of such 

 simultaneous observations as the Signal Service is now re- 

 ceiving from all seas and lands. Brault's charts give not 

 only the relative frequency of winds from each point of the 

 compass, but also the probability of strong and light winds 

 and calms, and furthermore the probable changes or order 

 of succession of the successive winds ; they are thus pecul- 

 iarly adapted to the needs of the mariner, and are undoubt- 

 edly an improvement upon the charts that have hitherto 

 been published at Washington, London, and Utrecht. 



The position and phenomena of the equatorial calm-belt 

 have been studied by Miihry with the help of the charts of 

 the London Meteorological Office. He finds that the lowest 



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