although its appearance is unaltered, it will exert dissimilar thrusts. An embankment of little height may be deposited in bad weather without slipping or subsidence, but when a high embankment is similarly tipped the surface of the earth is in an unfit state, and operations should be suspended for a few days. With regard to the systems of tipping and the prevention of slips, as a general rule an embankment should be deposited to the full width, for if it be not erected at one operation the earth may be of a different character in diverse conditions, and will be more exposed to the vicissitudes of weather; and in wide embankments, should the system be adopted of tipping two outer roads and one central road, the three tips should equally proceed in order that the earth may be in a similar state and be subject to equal exposure; or weathered surfaces will be created down which water will more easily percolate than through the solid mass. In the three tip system the two sides have a tendency to lean towards each other, and cause the greatest pressure to be upon the inner material during construction, and therefore the embankment is supposed to be more consolidated and less likely to slip; but, unless the conditions are exactly similar, the advantage of this arrangement is more fanciful than real, for should the inside slopes of the outer roads meet first, the earth deposited from the centre tip has not an equal distance to descend and, therefore, the mass has not been tipped from the same height, the looser material, temporarily or permanently, being upon the outer tips and the denser in the centre; whereas the slopes, being the most exposed, should be the more compact, and when they settle towards the centre without an outward movement at the foot, so much the better for the stability of the embankment. The pressure upon the seat is more regular when it is deposited to the full width, as weight is then not irregularly added, probably after some settlement. Instead of dividing the tips into two outer roads and one central road, and in that way endeavouring to obtain permanent stability, it is better to diminish the height the earth has to be cast, and to deposit it as far as practicable in lifts, and to the full width. In treacherous soils such as some of the clays, embankments that would not stand at a depth of 30 feet have been permanently stable when the seat was drained, and they were tipped in lifts of 15 to 20 feet in soft clay, and 20 to 25 feet in firmer clay, at double the height at which they previously slipped.