I90 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
the level of the phreatic waters during five months of summer 
and five months of winter, November rgor to October 1902, one 
is obliged to conclude that the devel of subterranean water in 
standing forest is lower than in the ground from which it has been 
cleared, both in summer and in winter, and that the oscillations of 
level are less in the standing forest.” 
M. Ototzky, persistently continuing his researches on this 
important point, is at this moment publishing a work in Russian, 
entitled, Subterranean Waters, their Origin, System and Distribu- 
tion, the second part of which, “Subterranean Waters and 
Forests, chiefly in the Plains of Middle Latitudes,” has just 
appeared. And M. Ototzky has also taken observations by 
means of chains of wells in the pine forests of the Lande of 
Gascony. 
Four plains regions in Europe, where the subterranean water 
zs absolutely stagnant and motionless, have thus been examined, 
and seem to show the same characteristics, but too little has yet 
been done in this direction for anyone to be able to formulate 
a general law on the subject. In place of the series of borings, 
as adopted by the Russians, M. Henry suggests a simpler 
method by means of pairs of wells, the construction of which 
he then proceeds to explain. 
In the tropics, where the evaporation from the earth is so 
much more marked, forests might not be found to have this 
influence on the level of the subterranean waters. The result 
of experiments carried on in different parts of the globe would 
throw much light on the relation between the evaporation from 
the soil, whether bare or cultivated, and the transpiration by 
forests. 
2. THE AIR Is MOISTER OVER GREAT WOODED AREAS. 
Of the whole rainfall, part is evaporated directly from the 
vegetation, another part is evaporated from the soil, a third 
flows away, a fourth lies in the surface-soil, reaching its 
maximum when the soil is saturated, a fifth is absorbed by the 
vegetation for its growth and transpiration, and the surplus only 
goes to feed the stratum of subterranean water. This surplus 
is less under woods, and therefore the amount of water absorbed 
in other ways must be proportionally greater. In plains, with 
which our investigations are concerned, there is no flow of 
