THE FOREST AND SPRINGS 377 



Forest (province of Cherson), M. Ototzky was led, since 1897, to formulate this theory, 

 that, all physico-geographical conditions being equal, the level of phreatic waters in the 

 forests of the region of the steppes is lower than in neighboring open spaces. In support 

 of these unexpected conclusions M. Ototzky published the results of a series of sound- 

 ings, of which some it is true are open to objection as proof positive of his theories. ^^ 



In 1897 M. Ototzky was directed by the Imperial Society to undertake some new 

 researches, but this time in the Province of St. Petersburg at 60° north latitude in a 

 region whose rainfall is much greater than that of the steppes, where he had worked in 

 1895 (23.6 inches annual rainfall instead of 11.8). 



He proved again that, under the forests where observations were made, the phreatic 

 sheet is depressed compared with what it is n neighboring cultivated regions. The 

 difference of levels is rather shght, and varied from 19.7 to 44.5 inches. 



On July 1, 1899, M. Henry, professor at the "Ecole Nationale des Eaux et Forets," 

 at his own request, was authorized to undertake at the expense of the "Administration 

 des Eaux et Forets" some soundings, with a view to verifying and completing the data 

 furnished by the Russian experimenter. 



The forest of Moudon near Luneville (Aleurthe-et- Moselle) was chosen for these re- 

 searches. It forms a large mass of woodland about 4,942 acres in extent (the altitude 

 varies from 807 to 873 feet). The soil is composed of strata of sand, gravel, and flint, 

 originating from the ancient alluvial beds of the Meurthe and the Vezouse, at the con- 

 fluence of which rivers the forest is situated. The water-bearing strata are met at a 

 slight depth, their upper level being given at depth of about 6.5 to 16.4 feet. A little 

 lower, about 23 feet or more, one finds an impermeable clay against which the infiltra- 

 tions are arrested. These different strata, and especially the last named, appear to be 

 horizontal. 



The rainfall in the forest was 28 inches in 1900 and 35 in 1901. The mean annual 

 temperature is 9° 4 C. (49° F.) with an average of + 1° 43 C. (345 F.) in winter and 17° 

 70 C. (64° F.) in summer. 



The forest is composed of oak, beech, and hornbeam ; it has been planted with storied 

 coppice in a rotation of 35 years in the greater part of its extent. Some small parts are 

 to be found covered with Scotch pine, the result of the replanting of ancient gaps in 

 the forest. 



In the spring of 1900 ten holes of 2 inches in diameter were drilled by the aid of the 

 Belgian geological borer, and these holes were lined with zinc tubes which had been 

 pierced with small apertures and furnished at their lower end with a similarly perforated 

 cone. Thus the earth was prevented from falling in and filling up the bottom of the well. 

 The numerous small apertures in the metal allowed the water easily to find its own level. 



Five holes were bored in bare ground in parcels of ground which had been cleared for 

 the use of the forest guardians, in the nursery gardens, and in the communal pasturage, but 

 always on the borders of the forest, the farthest removed being about a hundred meters. 

 Five others, destined to be compared with the preceding five, were made under the neigh- 

 boring woodlands, as nearly approaching the same conditions as it was possible to give. 



« Evidently it is well to operate only in ground which lies horizontally at the surface, 

 and which is of a homogeneous character to a great depth, so as to avoid the influence 

 of an uneven surface, and that of the undulations of the upper levels of deep impermeable 

 strata, whose projection may be very different from that of the surface. In stratified 

 ground, with strata alternately more or less permeable, the course of the subterranean 

 waters depends solely on the way these strata run, and can give us no notion of the 

 influence of the superficial vegetation. Unfortunately the ground in which M. Ototzky 

 first undertook his experiments appears to have been far from homogeneous, since he 

 found there in less than 16 feet of depth, three different well-defined spring levels. 

 Moreover the projection of the soil seems to have been taken very httle into account, 

 notably in No. 3 boring in the forest of Chipoff. 



