297 
subject to steady and in all probability periodic variations. and inter- 
changes, which are difficult to recognize in consequence of the mani- 
fold combinations of the numerous effective factors. Climatic 
changes, extending over long periods of time, are indicated by 
geological periods, which latter themselves demonstrate again only 
the gradual and not any sudden alterations of climate. Sudden. 
and even very moderate slow changes of climate cause the destruc- 
tion of the vital organism. 
The comparison of the climatic conditions of individual years, the 
differences in the yield of fruits of various kinds, as already men- 
tioned above, the unfavorable years in central Europe at the end of 
the sixteenth and eighteenth and beginning of the nineteenth cen- 
turies, and the very favorable seasons for grain and wine in the last 
quarter of the seventeenth and at the beginning of the eighteenth 
century and in the first third of the nineteenth century, together with 
the recurring failure under similar conditions of crops, particularly 
of wine, in 1847 and 1881, caused by the cool weather at the end of 
summer and beginning of autumn, in spite of the hot summer which 
had preceded it, etc., and furthermore the exact numerical researches 
based on results of observations of the meteorological elements, all 
show a variability of climate such as is accomphshed within a century, 
or even withm the lifetime of a man, and which can be most positively 
recognized from year to year, from decade to decade. To find the 
causes of these changes belongs to those who have devoted themsel¥es 
to researches in the laws of meteorology, and particularly to discov- 
ering the methods by which to prognosticate the conditions of weather 
for long periods in advance. — 
Distribution of good and poor wine crops, by decades, since 1600. 
[From Fritz (1889), p. 301.] 
> 
Germany Switzerland Germany Switzerland 
(Rhine). (Zurich). (Rhine). (Zurich). 
Decade. | Above} Below | Above] Below Decade. Above | Below | Above | Below 
aver- | aver- | aver- | aver- aver- | aver- | aver- | aver- 
age. | age. age. age. age. | age. | age. age. 
1600-1609. __...-.. pase Saeeae 8 1 9 || 1760-1769 ..____.- 4 | 6 5 5 
HGIO=1619E ee. jeet etn ees ee 4 OOO eee = 5 | 5 7 3 
H620=16292 22025 -= | Saad Pee nee 2 8 || 1780-1789 _______- 5 5 8 2 
LG80S1GS9 22s oe Semi oe ecaeh ace 3 4 6 || 1790-1799 ....__.- 2 8 8 2 
1640-1649. __...... 1 9 2 8 |} 1800-1809 .......- 5 5 5 5 
1650-1659. -_.__-_- | 2 8 3 7 || 1810-1819 _______- 4 6 2 8 
1660-1669____.___- | 2 8 5 5 || 1820-1829). .-- .-.- 4 6 6 4 
167O-1679_ | 3 7 5 5 || 1830-1839 -....-.- 5 4 5 5 
1680-1689. ________| 4 6 7 3 || 1840-1849 _______- 3 uf 6 4 
1690=1699-" .= -- = | 3 7 1 Oa el 850 =1 850 eee 4 6 4 6 
147 (0, 00S ee | 5 5 6 4 || 1860-1869 _____..- 4 | 6 6 4 
PAOD 22.2. | 5 5 4 6 || 1870-1879 ._._...- 4 6 2 8 
UiQ0=1729"" Nee 8. | 6 4 9 6 || 1880-1887 --..---- 2 6 p 6 
1730-1789. __.__--- | 3 i 5 5 Gxt 
1740-1749. --___._- 6 4 | 3 7 average.| 3.9 6.0 4.5 5.4 
5017598 5 5 5 5 
