To prevent embankments of little height as in “forming,” spreading, slipping or weathering, as they are usually constructed from side cutting and loose top soil, the sods over the site of the side cutting should be removed and a turf wall be made of them on each side of the formation, the excavation being deposited within them, when it will settle equally and become consolidated, the wall preventing it spreading and also saving expense in maintenance. In an embankment of soft earth that weathers quickly, the tipped material should be allowed to take its natural slope, and then every effort should be made to prevent its equilibrium being destroyed. Where heavy and sudden rainfall occurs the edges of the formation have been purposely tipped and maintained from 6 to 12 inches above the height of the centre, in order to prevent during construction gutters or eroded channels being formed upon the slopes, the central portion being drained and the water led away. However, aqueous action may not deleteriously affect earth when tipped into an embankment notwithstanding that the soil cannot be made in the same state as before excavation, and that deposited material is more open and subject to percolation than the solid unexcavated earth; on the other hand, although the percolation and degree of exposure to the atmosphere are greater, in some soils this may tend to drain and render them harder and more stable. In fact, special circumstances may alter the general behaviour of any earth, but the material forming an embankment should be regarded as in the same condition as if it had been exposed to meteorological influences, and it should be remembered that in railway, dock, or canal works the deposited earth is seldom uniform throughout, it being either soft at one place and hard at another, or intermixed in a manner unknown in nature, and that exceptionally difficult cases may occur which can hardly be treated by any particular method of procedure or even in the way which experience has proved to be effectual in several instances in similar soils under apparently like conditions. The system of tipping has some influence upon the stability of an embankment and the prevention of slips and subsidences. The first operation is the preparation of the ground upon which an embankment will be deposited. Solid hillocks or firm mounds that in any way tend to arrest motion should not be removed, but vegetable or bush growth should be destroyed, and where slips and subsidences are likely to occur, turf and all soft soapy matter should be stripped so that the deposited earth rests upon a sound stratum. In the dyke countries of North West Europe, before an embankment is deposited, care is taken to remove all trees and roots so as to effect a thorough connection between the ground and the earth forming the embankment.