— 8 — 



The lov/er layer commenced to thaw on the 26-th of February, when 

 the thermometer rose above 0° at a depth of 80 cm. At a depth of 40 

 cm. the thermometer remained below zero until the 4-th of April. This 

 temperature evidently extended deeper than 40 cm. until the 4-th 

 of April. 



After the 1-st of April the upper part of the frozen layer began to 

 thaw quickly, getting ever thinner, so that by the 3-rd of April it was 

 no thicker than 10 cm. and lay at a depth between 35 and 45 cm. 

 On the 4-th of April both processes of thawing, the upper and the lo- 

 wer, met at a depth of 40 cm. and all the thermometers on that day at 

 all depth rose above zero. And all the water in the soil -layer turned 

 into a liquid condition. 



Many years direct investigation of soil moisture at a period of full 

 thaw — this moment always coincides with the commencement of spring 

 field work has not shown any quick movement of soil water from the 

 upper belts into the lowers ones; and this alone should prove that very 

 little snow-water had found its way into the soil. As far as I know no 

 statistics have been furnished on this matter. 



A small accumulation of water, about 3 to 4 per cent, in the 

 upper belts near the surface to a depth of 10 to 20 cm., may be obser- 

 ved in certain years, when spring comes in early. But if the thaw is 

 protracted, owing to a cold spring, the sub-surface gets extremely dry. 

 And by the time spring work begins, we find less water than there was 

 during the course of the winter. 



The accumulation of large masses of snow in woods and especially 

 in artificial steppe plantations in the form of narrow strips or belts, give 

 a somewhat different effect. Here the snow holds out one or two weeks 

 longer than on the neighbouring fields; and when the soil of the conti- 

 guous fields has already thawed at all depth, it is still in a frozen con- 

 dition in the woods, under the snow. Water from the melting snow in 

 the woods getting into the soil on the boundary between the frozen and 

 the thawed parts is almost wholly absorbed and serves as a sourse for 

 the accumulation water for the forest. 



J. Jukow recommends strewing ashes over the surface of the 

 snow in strips; and affirms that under these strips the snow melts quicker 

 than it does on the neighlouring clean snow strips, and that by this 

 means the snow-water is imbibed into the soil. Of course, if there was 

 no evaporation, the water thus formed would remain on the surface until 

 a certain thickness of the soil layer thawed. But the process of evapo- 

 ration is a reality and is particularly powerful in spring. Towards the 

 period when spring tillage commences the ash-strewn strips dry up and 



