There are two modes of installing the system: either the rope passes above the cars and is carried by them, resting in the clips, or it is carried under the cars on rollers, the cars being attached by clips or a gripcarriage.
To prevent this various implements, such as disk harrows and specially constructed rollers, may be used to consolidate the upper stirred portion of the soil and place it in close capillary relationship with the lower unmoved layer.
The pipes are best supported on rollers which allow of movement without straining the joints.
In Louisiana two mills, set one behind the other, each with three rollers 32 in.
Long, and driven by one engine through gearing of 15 to 1, are speeded to have a surface velocity of rollers of 25 ft.