WarkgR.—On State Forestry. XXXl 
School at Nancy, and M. Fantral, of a more recent date. He states that 
the results M. Mathieu has ‘obtained are singularly uniform, and they 
have been reproduced so often that even so careful and conscientious an ob- 
server as M. Mathieu considers that they may be held to be dependent on a 
general law of nature. His observations lead to the conclusion that while 
on the one hand forests tend to lower the general temperature of a country, 
and so to promote the fall of rain at regular intervals, and in moderate 
quantities ; on the other hand they ward off sudden meteorologieal changes, 
which are dangerous inasmuch as they cause sudden and heavy falls of rain, 
which result in floods and other like disasters. M. Fantral's results corro- 
borate those of M. Mathieu; and M. Cantegiel, Inspector of Forests, near 
Toulouse, in the extreme South of France, has also carried out a similar 
Series of observations, extending over a number of stations, with precisely 
similar results. Boussingault’s example of the Lake of Valentia, in Vene- 
zuela, has been often questioned. This lake has no known outlet, and when 
Humboldt visited it the water was decreasing in & marked degree, the 
forests in the neighbourhood being at the same time largely eleared. 
Twenty-five years later, Boussingault found its dimensions increasing, 
which he ascribes to the War of Independence having occasioned a cessation 
of clearing, so that less timber was being cut down and a new growth 
springing up. He infers that this is the true explanation from the fact 
that other lakes in the neighbourhood, around which the forests had been 
left in their natural state, had shown no such fluctuations. The lakes of 
Neufchatel and Geneva have also been mentioned by Humboldt and Jaus- 
sure as instances of the same result. The case of the island of Ascension 
seems very conclusive, as it appears matter beyond doubt that the only 
spring in the island was dried up when the trees were removed, and com- 
menced to run again when the forests were restored. St. Helena is also 
quoted as an instance in point, as are Mauritius and St. Vincent, the dis- 
trict of South America lying between the Orinoco and the Andes, and many 
other localities. I have myself observed the drying up of springs and de- 
crease of the average amount of water in some of our mountain forests in 
India in which extensive clearing has taken place, and think there can be 
no reasonable doubt that such clearing does affect injuriously the supply 
of water for springs and permanent supply in the streams and rivers. Hof 
Rath Wex, in a paper contributed to the Vienna Geographical Society in 
1875, actually states that the decrease of water in the Elbe and Oder has 
been 17 inches; Rhine, 24; Vistula, 26 ; and Danube at Orsova, 55 inches 
in 50 years. Not less conclusive in my opinion is the evidence at our dis- 
posal regarding what M. Clané calls the mechanical action of forests 
through the roots in retaining in its place the earth, especially on the sides 
of mountains and hills. 
