DISTRIBUTION OF RAINFALL. 287 



years the amount of life and property destroyed is enormous.^ The 

 consequences of these floods in other countries, more especially in the 

 Alps and Pyrenees, have been so disastrous, and the causes so appar- 

 ent, that the governments of France and Switzerland have, in recent 

 years, taken extraordinary care to prevent their recurrence, and with 

 reasonable prospect of entire success. The methods employed to effect 

 this object will be more fully described on a subsequent page. 



In comparing the climate of the United States with that of Russia, 

 ■we find some points of resemblance that deserve notice.' The greater 

 part of that country and of Western Siberia belongs to the region of 

 summer rains ; yet it is divided into two well-marked zones, with different 

 vegetation — the forest region and the steppes. In the former of these, 

 the most rain falls iu July and August, and in the latter in June. In 

 its meteorological relations, the steppe is a region where arborescent 

 vegetation is interrupted, or at least greatly checked, from want of moist- 

 ure. This want of humidity reveals several distinct characteristics, 

 such as the want of rains in the summer season, extreme dryness of the 

 air, and an arid soil. This latter condition is the most important, be- 

 cause if it could be neutralized either by natural infiltration or by irriga- 

 tion, we might have trees in the driest country in the world. Less rain 

 falls iu summer iu the south of France and in a large part of Italy than 

 in Southern Eussia; but these countries have no steppes, and the cul- 

 tivation of trees has there been long regarded as among the surest 

 branches of rural economy. In those countries, however, the autumn is 

 rainy, the fall of rain averaging 3 to 3^ millimeters a day, so that the 

 deeper strata of the soil imbibe the water, and are able to supply to the 

 roots the moisture evaporated from the leaves, through the long summer 

 droughts. 



On the steppes, however, the greatest amount of rain falls in June, 

 as heavy showers, which flow off on the surface, until lost in the ravines. 

 The autumn is dry, and the winter neither long nor snowy. The melt- 

 ing of snows in spring affords but little water. But in Northern and 

 Central Russia the case is different. The annual amount of rain is but 

 a little more than on the steppes, but the snow falls deep, and lies on 

 the ground through five months of the year. When it melts, it sinks 

 deeply into the soil. Besides this, the summers are cooler, and the 

 rains ofteuer fall in fine, misty, and protracted showers. This explains 

 the great difference between these two "zones, although both belonging 

 to the region of summer rains. 



It is moreover impossible to trace with exactness the boundaries of 

 the steppes. The forests begin to disappear on exposed southern slopes, 

 in elevated regions, and where the soil is dry ; then the forests will 

 appear only along the rivers; and at last the trees will be found only iu 

 locations where there is a natural infiltration, or irrigation. 



Along the Baltic we have a belt of autumnal rains and heavy forest 

 growth. In the Ural Mountains there is less exposure to severe droughts, 

 but farther south we find a zone of June maximum, and in its principal 

 features the distribution of the rains follows the following order : After 



1 A memorable flood in the Genesee River, New York, began March IG, 1865, and 

 caused by the rapid melting of deep snows in the hills around its upper waters, by 

 warm winds and rains, is estimated to have caused a loss of not less than $1,000,000 

 in the city of Rochester, and some estimates lix the loss at three times this amount. 

 Had these snows been reasonably sheltered by woodlands, it is quite certain that 

 they would have melted more slowly and probably without injurious results. 



^ The facts in this statement, so far as they relate to Russia, are condensed from an 

 article by A. Wojeikof, in the Eepertorium fiir MeteoroJogie, published by the Imperial 

 Academy of Sciences, St. Petersburg (1870), vol. 1, part 2, p. 187. 



