518
EXPOSITION AT VIENNA.
The soil is kept in a proper condition of dryness in part by drains and in part by open ditches, some of which soak up the water, while others carry it off. These have various dimensions, and a length in all of 216,400 feet, or forty-one miles. The water in them should never rise beyond a foot’s distance from the surface of the soil. The snow and rainwater is conducted to these ditches by the furrows left in ploughing, and in part also by others made at right angles to the latter, which should be as numerous as possible.
The number of the ditches depends on the width of the field, for the cross-furrows cannot be made very long without danger of being filled and washed away by the water.
This is the only way of keeping ploughed land dry in winter, and of avoiding the injurious effects on the winter-seed of moisture, accompanied by alternate thawing and freezing. Frost increases the volume of moist earth, and, at the same time, raises the plants and tears up their roots. These then become sickly and die, or are even drawn entirely out of the earth.
It is easily understood that in such an extensive system of ditches as exists on these farms, the width and depth of each must be correctly proportioned in order to prevent an overflow. I have known cases, however, where this apparently simple precaution has unfortunately not been taken. The ditches should be enlarged at each point where they receive a new supply of water, and sufficiently enlarged to take this up. Thus the main ditches must have a capacity equal to that of all the smaller ones emptying into them.
The spring-water is used for supplying the farms and the pond for the game in the deer-park. The inundating water is dammed up for irrigation of the meadows.
I have adopted a simple means for crossing the large number of ditches on my farms. These must always remain open for draining the swampy land, and bridges are expensive, and liable, if of wood, to be stolen. On the regular wagon-roads the approaches to the ditches are made with a slope, and even where they are six feet deep it is customary to drive through them. In other cases bundles of branches or fascines are laid temporarily across, and afterwards carried back to the sheds, where they are stored.