All saturated or wet earth should, if practicable, be run to spoil, but it is not easily effected, as it cannot well be filled into one waggon of a set, for it may be present throughout the whole surface of a cutting, nor in variable weather can operations be conveniently suspended until the exposed faces of a cutting are dry, but means are generally available by which any serious deterioration may be lessened. No turf, mould, mud, peat-moss, soft pasty earth, frozen soil, or snow, should be deposited in an embankment, but only firm earth; and no solid lumps of large size intermixed with shovelled material unless they are broken up and trimmed when tipped, as the absorption of water will be greater in the earth having the smaller particles; and should it happen that several waggon-loads of such material are tipped and are succeeded by others containing large lumps, an embankment cannot be a homogeneous mass, but will consist of more or less consolidated portions in a comparatively dry state, and others which are less impervious and therefore more subject to the effects of water and settlement. All snow or frozen soil or muddy earth should be cleared away from the spurn head, and if it can be avoided no material should be tipped in bad weather. With respect to the loosening of the soil by the process of tipping, taking into consideration that railway embankments are almost invariably formed in masses of 2, 3, or 4 cubic yards, according to the capacity of a waggon, it is obvious almost the whole bulk has been disturbed, and that the condition of the solid earth in a cutting is not maintained, for the soil in addition to being unbound by the process of excavation, casting into waggons, and shaking during transition, is ejected with force down the slope of the tip, the impetus having to be dispersed. It is certain the size of earth waggons cannot conveniently be much increased, and that little would be gained if a cubic yard or two were added to their contents; and that the higher an embankment the greater the velocity of the soil down the slope of the tip and the loosening action which causes the earth to be lighter and to take a flatter slope than when deposited in layers from a moderate height, also the greater the length of the lead, the greater the vibration and agitation. In the case of certain soils the particles of which become soft or dissolved when in a wet state, such as sandy clay, loamy soil, and some varieties of clay, _vide_ Chapter II., the effect of a long lead or even a short one will be that the more solid portion of the contents of a waggon will settle, leaving the loose or mud at the top, and when a waggon is tipped the loose top “slurry” will roll down the tip almost as a fluid and proceed beyond the spurn head, thus making a wet sliding surface, the bottom toil frequently remaining in the waggons and requiring to be excavated from it. Nothing can be done in such a case but wait until the