F. Walda — Bruckner^s Klimaschwankungen. 143 



Year. Amount in Meters. Year. Amount in Meters. 



1830 + -40 



915/21 4- 8-8 1843/46 —059 under this. 



12 century — 4-2 1847 +0-22 higher than this, 



1306/07 + 11-2 falling 1809/14-1845 



1638 + 4-9 1851/55 -0-21 falling 1847-1856/60 



1715/20 .about + 0'3 1856/60 — 0*27 rising 1845-1847 



1715/43 rising 1861/65 —0-19 



1744/66 falling 1866/70 +0-19 rising 1866-1878 



1767/80. rising (?) 1871/75 +0-17 



1815 +2-40atleast 1876/78 +0*54 



1730/40 to 1809/14, ) 

 a relatively high level. ) 



There are, consequently, maxima about 1743, between 1780- 

 1809 and 1847-1879 ; and minima about 1715, 1766, 1845 and 

 1856-60. Bruckner places the average duration of an oscilla- 

 tion at about 34 to 36 years. That these oscillations are due to 

 large sectional climatic influences is very evident. A compari- 

 son with the oscillations of rainfall and temperature shows that 

 for the period since 1840, these are accompanied by oscillations 

 in this sea level. 



For the region west and north of the Caspian Sea, there 

 occurred wet, cold periods about 1745, 1775, 1810, 1845, 1880 ; 

 and dry, warmer periods about 1715, 1760, 1795, 1825, 1860. 

 These changes affect the inflowing rivers, which in turn change 

 the level of the sea. A comparison with the table of sea levels 

 shows the increase with cold, wet periods and decrease with the 

 dry, warm periods. There are long periods of oscillations in 

 addition to the short period fluctuations. 



An investigation of a number of lakes gave the following 

 results : 



(1.) The oscillations of the true river-lakes are small and 

 follow without retardation the river oscillations. 



(2.) The oscillations of lakes having no outlet are large, and 

 the epochs show a retardation in relation to the corresponding 

 epochs of the inflowing streams : the maximum height of the 

 lake may occur at the time the receding inflowing streams have 

 reached an average height. 



(3.) Lakes having no outlets have a slighter retardation in 

 the case where the inflowing streams have large oscillations 

 than for those where the oscillations are small ; and the same 

 is true of lakes with low banks in contrast with those having 

 high banks. 



(4.) Small secondary oscillations of the influx in lakes having 

 no outlet are without marked effect when the difference of the 

 inflow and diminution still retains the same sign. The only 

 effect is to accelerate or retard the rise or fall of the water. 



