78 Messrs. W. N". Shaw and E. W. Cohen. On the Seasonal 



cases the higher orders are entirely negligible. At Valencia and 

 Aberdeen, however, the amplitude of the third-order curve approaches 

 one-third of that of the second-order curve, and therefore becomes more 

 important ; but its amplitude amounts to only one-third of a degree, and 

 the second-order effect tlms remains the only one of any practical 

 importance. 



Mr. A. A. Eambaut* has harmonically analysed the curve of the 

 monthly mean temperatures for a single year (1899) at Oxford with a 

 similar result, and in this case, as in the analysis of the 1884 Kew 

 temperatures, the second-order curve is comparatively very large. It 

 will be seen that all the stations hitherto mentioned have been on or 

 near the sea-coast, and indeed it may be said that all British stations 

 are comparatively near to a sea-coast. It was therefore thought ad- 

 visable to make an investigation of the temperatures at a Continental 

 station, where the effects due to the proximity of the ocean \vould be 

 eliminated. For this purpose Vienna was chosen. Dr. Hann, in a 

 paper on the " Temperature of Vienna, " based on observations for 

 100 years, gives the harmonic analysis of the curve of mean daily 

 temperatures (Table I, Vienna). The amplitude of the second-order 

 curve is only -^th of that of the first-order curve, and that of the 

 third-order curve is approximately of the same magnitude. Moreover, 

 the weather at Vienna has been investigated for the years 1876-1880 

 in the same way as the weather at Kew, and curves of temperature 

 difference from the first order curve value have been drawn for each 

 wind and each type of weather. No definite periodic curves were 

 obtained similar to those obtained for Kew, all the curves being dif- 

 ferent from one another, and in themselves irregular : the only universal 

 characteristic was that the cyclonic and anticyclonic curves for the 



DIAGRAM 7. 



DIVERGENCE FROM FIRST ORDER CURVE. 



VIENNA 1876 TO 1880. 

 DEC. JAN. FEB. MAR. APR. M AY J UN. JUL. AUQ. SER OCT. NOV. DEC. 



Thick. During cycionic weather. 

 Thin . asiticycionic. 



whole year (Diagram 7), and moreover for each wind, showed a re- 

 markable parallelism, the cyclonic being almost always a little warmer 



* ' Rov. Soc. Proc.,' vol. 67, p. 221. 



