320 
FUTAIEj OR FULL-GROWTH SYSTEM. 
proaching to maturity, the original processes already desciibed 
are repeated; and as, in different parts of an extensive forest, 
feet wide, by horizontal ditches closed at both ends, and thereby obtained, 
from firs of different ages, shoots double the dimensions of those which 
grew on a dry soil of the same character, where the water was allowed to 
run off without obstruction.”—D umont, Des Travaux Publics , etc., pp. 
94-96. 
The ditches were about two feet and a half deep, and three feet and a 
half wide, and they cost about forty francs the hectare, or three dollars the 
acre. This extraordinary growth was produced wholly by the retention 
of the rain water in the ditches, whence it filtered through the whole soil 
and supplied moisture to the roots of the trees. It may be doubted 
whether in a climate cold enough to freeze the entire contents of the 
ditches in winter, it would not be expedient to draw off the water in the 
autumn, as the presence of so large a quantity of ice in the soil might prove 
injurious to trees too young and small to shelter the ground effectually 
against frost. 
Chevandier computes that, if the annual growth of the pine in the 
marshy soil of the Vosges be represented by one, it will equal two in dry 
ground, four or five on slopes so ditched or graded as to retain the water 
flowing upon them from roads or steep declivities, and six where the 
earth is kept constantly moist by infiltration from running brooks.— 
Comptes Rendus d VAcademie des Sciences —t. xix, Juillet, Dec., 1844, 
p. 167. 
The effect of accidental irrigation is well shown in the growth of the 
trees planted along the canals of irrigation which traverse the fields in 
many parts of Italy. They flourish most luxuriantly, in spite of continual 
lopping, and yield a very important contribution to the stock of fuel for 
domestic use; while trees, situated so far from canals as to be out of the 
reach of infiltration from them, are of much slower growth, under circum¬ 
stances otherwise equally favorable. 
In other experiments of Chevandier, under better conditions, the yield 
of wood was increased, by judicious irrigation, in the ratio of seven to one, 
the profits in that of twelve to one. At the Exposition of 1855, Chambre- 
lent exhibited young trees, which, in four years from the seed, had grown 
to the height of sixteen and twenty feet, and the diameter of ten and 
twelve inches. Chevandier experimented with various manures, and 
found that some of them might be profitably applied to young, but not 
to old trees, the quantity required in the latter case being too great. 
Wood ashes and the refuse of soda factories are particularly recommended. 
I have seen an extraordinary growth produced in fir trees by the applica¬ 
tion of soapsuds. 
