378 APPENDIX 



There were, therefore, five pairs of borings. 



Observations were made once a month from May 4, 1900, to August 24, 1902. 



The levehng was done by the pupils of the "Ecole Forestiere" in May, 1900, and May, 

 1901, in taking for the initial point the altitude of the Station of Marainvilhers which is 

 about 790.1 feet. 



One will find in the following table (page 379) all the measurements taken at Moudon; 

 none have been omitted (abridged in translation) . 



We have been obliged, however, to omit the report of one of the five pairs, of which 

 one bore was made in the fields of the farm of St. George and the other in the neighbor- 

 ing coppice (third cutting in the third series of coppices) because the bore made in the 

 field was destroyed by the plow in March, 1901. 



The figures of the table (page 379) give the immediate results of the measurements 

 effected, without taking into account the difference in the altitude of the orifices of 

 the borings. 



If all the measurements are reduced to the same horizontal level, one finds that 

 the level of the water under the forest at all seasons is lower than that under bare ground: 

 By 11.8 inches for the first couple, 7.9 for the second couple, 16.5 for the third couple, 

 12.2 for the fourth couple. 



It is certain that the difference of level is more accentuated than these figures would 

 indicate, since one knows that in permealjle soils the phreatic sheet follows the varia- 

 tions of the outline relief of the stratum, although with far less pronounced undulations. 



But let us accept the preceding figures as unquestionable minima whose average is 

 11.8 inches. 



We can affirm that, according to the measurements effected each month from May 4, 

 1900, to August 24, 1902, in eight borings made at random, sometimes under the wood- 

 lands, sometimes under the bare ground near the forest of Moudon (Meurthe-et-Moselle) 

 the level of subterranean waters at all seasons is at least 11.8 inches deeper under the 

 woods than it is outside. 



The experiments of M. Henry, carried out regularly for a period of 28 months have 

 further brought to light the following facts, which are absolutely new. 



The oscillations in the level of phreatic waters is less under the woods than in the 

 open. The infiltration, too, is slower in the forest. The maxima and minima occur 

 about a month later than those observed outside of the woods. 



One sees here that the forest plays the same role of regulator and stabihzer which one 

 recognizes it to do with regard to the temperature. 



Some experiments made quite recently by M. Ototzky, an account of which has been 

 pubhshed in Russian in the fourth number of 1902 of the Magazine "La Pedologie," 

 and of which a French translation by M. A. de Lebedef, attache of the "Ministere de 

 LTnterieur " at St. Petersburg, is in the press has still further confirmed these facts. 



M. Ototzky's experiments were made at the " ficole forestiere" of Staraia Rossa 

 (province of Novgorod) at 58° N. latitude, near to the Lake of Ihnen. " One is obliged 

 to conclude," says M. Ototzky at the end of his article, "that the level of subterranean 

 water is lower in the forest than in the stratum exploited, in summer as well as in winter, 

 and also that the oscillations are less }^ 



To sum up, we seem to have gained the information that in the forests of 

 the plains in temperate or cold climates," whose soil is formed of homogeneous 



^^ Quotation borrowed from M. Henry (Revue des Eaux et Forets, 1903, p. 197). 



^^ In the tropical region of the globe where the heat is torrid, it is physical evaporation 

 from the soil which plays the preponderating part, while physiological evaporation does 

 not increase with the temperature. It may be, therefore, that in this case the level of 

 the subterranean waters is even higher in the forest. M. Ribbentrop has vouched for 

 this fact near Madras (Revue des Eaux et Forets, 1901). 



