1869.] Meteorology. 127 



International ' issued by tlie Observatoire Imperial ; and they give 

 for 8 A.M. every day the conditions of pressure, wind, sea-disturb- 

 ance, and character of the sky, which have been obtained fi-om 

 ships' logs and land observations. The materials have been partly 

 procured by the system of international co-operation ; our own Me- 

 teorological Department and the Army Medical Department having 

 contributed copies of observations furnished to them. 



The value of a work like this for precise inquiries depends on 

 the accuracy of the data furnished on the charts; and in this 

 important particular we regret to say that the present Atlas leaves 

 something to be desired. 



It is naturally quite impossible to ensure absolute synchronism 

 in the observations themselves, when the observers are scattered over 

 so extended an area. Kecourse must therefore be had to methods 

 of interpolation, so as to reduce the results to what they would 

 have been at 8 a.m. Paris time. This necessarily introduces a very 

 serious amount of uncertainty. As regards the graphical repre- 

 sentations, the isobaric lines have been drawn with a very free hand. 

 In the preface M. Le Verrier says: "In the determination of iso- 

 baric curves the consideration of the winds is most important. 

 They indicate to us the modifications which the curves undergo 

 in the process of bringing themselves into harmony with each 

 other, and explain to us sinuosities and irregularities which seem at 

 first sight to have no apparent cause." Such an admission as the 

 foregoing does away with the scientific value of these curves alto- 

 gether. How is it possible to deduce any relation between wind 

 and barometrical pressure, when the wind itself has been already 

 taken as an important element in the determination of the course of 

 those curves? This is arguing in a very limited ch'cle indeed. 

 However, the observations themselves appear to have been entered 

 on the charts with aU possible care, considering the difficulty of the 

 preliminary calculations. The preface contains a most interesting 

 accomit of the gradual development of the various meteorological 

 undertakings carried on by the Observatoire Imperial. 



In addition to this Atlas, two other volumes have appeared 

 under similar auspices, the 'Atlas des Orages,' 1865, and the 'Atlas 

 Meteorologique,' 1866. These, have reference almost exclusively 

 to the distribution of thunderstorms and of hail over France during 

 the years to which they respectively refer. The entire series of 

 charts is most beautifully lithographed, and the whole is a valu- 

 able contribution to science. 



Holland may take the next place, where the Koyal Meteorological 

 Institute at Utrecht, inider the superintendence of Professor Buijs 

 Ballot, assisted by Lieut. Cornelissen for the Marine branch, con- 

 tinues to work steadily, especially in the department of Ocean 

 Meteorology. Owing to these publications being in Dutch, their 



