THE HISTORY OF DRY-FARMING 379 
ture which, viewed in the light of our modern know]- 
edge, is little short of marvelous. The chief inspira- 
tion of his system came from a visit paid to south 
of France, where he observed ‘‘near Frontignan and 
Setts, Languedoc” that the vineyards were carefully 
plowed and tilled in order to produce the largest 
crops of the best grapes. Upon the basis of this 
observation he instituted experiments upon his own 
farm and finally developed his system, which may be 
summarized as follows: The amount of seed to be 
used should be proportional to the condition of the 
land, especially to the moisture that is in it. To 
make the germination certain, the seed should be 
sown by drill methods. Tull, as has already been 
observed, was the inventor of the seed drill which 
is now a feature of all modern agriculture. Plow- 
ing should be done deeply and frequently; two 
plowings for one crop would do no injury and fre- 
quently would result in an increased yield. Finally, 
as the most important principle of the system, the 
soil should be cultivated continually, the argument 
being that by continuous cultivation the fertility 
of the soil would be increased, the water would 
be conserved, and as the soil became more fertile 
less water would be used. To accomplish such culti- 
vation, all crops should be placed in rows rather far 
apart, so far indeed that a horse carrying a culti- 
vator could walk between them. The horse-hoeing 
idea of the system became fundamental and gave 
