56 



(8) Mild, and at the same time dry, winters are associated with a. 

 tendency of the earth temperature' to rise above the average. 



(9) The earth temperatures exhibit a tendency to fall, if not al- 

 read}' too low, during winters in which, with alternate freezing and 

 thawing, the mean temperature is below the normal. 



(10) In the same way even a covering of snow can only to a lim- 

 ited extent prevent the cooling of the earth when severe cold follows 

 the mild and rainy weather of the first part of winter. 



(11) In continuous severe winters, on the contrary, wdien even 

 December generally brings a permanent covering of snow, the nega- 

 tive departure of the earth temperature is either limited to the higher 

 strata or is unimportant. 



(12) A warm spring, which, as a rule, brings only a moderate quan- 

 tity of rain, causes a relatively decided rise of the earth temperature. 



(13) When a cold and rainy late winter is directly succeeded by 

 warm spring months, the temperatures of only the upper strata of 

 the ground rise, wdiile those of the low^er strata may fall still further 

 below their normal values. 



(14) In certain w^arm and at the same time rainy springs the earth 

 teniperatures remain on an average unchanged with respect to the 

 nonnal for the cold rain counterbalances the warm weather. C. A.] 



(15) An exceptionally cold spring, which is generally distinguished 

 by heavy snow^s, is, with few exceptions, accompanied, and to a con- 

 siderable depth, by a notable low^ering. of the temperature of the 

 ground in comparison wath its normal temperature. 



(16) In cold and at the same time dry spring weather the relative 

 lowering of the temperature of the ground will generally be incon- 

 siderable if it has not been preceded by an immediate very rainy 

 season. 



(17) A warm summer is always accompanied by a high temperature 

 of the ground or by a rise of its temperature. The increase is the 

 more decided the more the excess in the temperature of the air is 

 accompanied by a large quantity of rain, or has been immediately 

 preceded by it. In warm and comparatively dry summers the rise 

 of the earth's temperature does not perceptibly exceed the normal. 



(18) The relative lowness of the temperature of the soil which fol- 

 lows without exception a cool summer generally extends down only 

 to a comparatively moderate depth, scarcely to 4 meters. Those 

 months in which we find it extending to G meters will be found to 

 have been at the same time rainy months. 



(19) A warm autumn, with very few exceptions, causes a corre- 

 sponding small rise in the temperature of the soil, but this may even, 

 on the contrary, become a fall wdien the late autunni, by reason of 

 much rain, resembles a mild type of winter. 



(20) Low air temperature is generally accompanied in autumn by 

 an excess of rain, the consequence of which, as regularly and fre- 

 quently observed, is a falling in the temperature of the earth. 



(21) In the rarer cases of cool and dry autumns there is observed 

 only a very inconsiderable influence on the temperature of the earth. 



(22) The dampness of the soil is (under the climatic influences 

 prevailing in ^funich) sufficient to allow^ the variations in the tem- 

 perature of the air in winter and spring to exercise a decided influence 

 upon those of the soil, whereas in summer an excess of rain would be 



