PHYSICS OF THE GLOBE. 165 



years of observations upon thermometers placed at altitudes 

 varying from four to twenty-four feet conduce to the same 

 result. The greatest irregularities are, however, met with in 

 ascensions to considerable heights, and much more knowl- 

 edge on this subject is greatly to be desired. 



Guldberg and Mohn have published two articles on the 

 Vertical Diminution of Temperature in the Atmosphere. 

 Their essay goes over a ground already pretty fully trav- 

 ersed by Thomson, Reye, Hann, etc., but presents some feat- 

 ures of the subject in a rather new aspect. Their formulae 

 relate to a stationary atmosphere and to ascending and de- 

 scending currents. 



Alluard communicates to the Academy at Paris the re- 

 sults of observations, on the Puy-de-Dome, on the Nocturnal 

 Variations of Temperature at Different Altitudes. He has 

 studied the minimum, maximum, and mean temperatures, 

 from January to August, 1878, at the summit and at Cler- 

 mont. During these months he finds 49 cases in which the 

 minimum temperatures at the summit are decidedly warmer 

 than at the base, and he concludes that during the ni<>-ht- 

 time the temperature varies with altitude in an entirely dif- 

 ferent manner from what it does by day. 



The most important work on atmospheric temperatures 

 received during the year is the first part of Wild's "Tem- 

 peratur-Verhaltnisse" for the Russian Empire, which great 

 work will eventually include all questions relating to the 

 distribution of temperature throughout Asiatic and Europe- 

 an Russia. The present volume is confined to the prepara- 

 tory work of collecting and criticising the material at hand, 

 and especially to the investigation of the diurnal tempera- 

 ture periods, as shown by series of hourly or other frequent 

 observations. Wild declines to present the laws of diurnal 

 variations in the form of the Lambert formulas, and confines 

 himself to the graphic method of plotting and interpolation 

 by means of free-hand-drawn curves. The reasons for this 

 important step are fully and forcibly given, and consist in 

 the utter insufficiency of the Lambert formulae to represent 

 the observations unless from eight to sixteen terms are em- 

 ployed, which leads to great and unnecessary labor, and even 

 then introduces erroneous times of maximum and minimum. 



Wild concludes this portion of his work with a series of 



