In embankments in loose soil and across valleys, especially if they are narrow and deep, repeated gusts of wind which have their maximum effect upon a flat surface at right angles to it, will produce a hammering action upon the windward side, and when the velocity is very great, upon the leeward portion there may even be a partial vacuum created by the wind rushing over the top of an embankment. An actual maximum momentary pressure of wind of 80 lbs. per square foot was registered at the Liverpool Observatory in 1869, equal to a hammering action of 0·55 lb. per square inch. It is here referred to in order to show that in exposed valleys the surface of all embankments of light soil should be covered so that the particles cannot be blown away at the top or from the slopes, for a force of 80 lbs. per square foot nearly equals the weight of a cubic foot of dry open sand which cannot be taken as weighing much more than 90 to 100 lbs. If seed be sown upon a slope it is evident that it should be of uniform kind in order to create a general equable condition, and the growth of all rank vegetation should be prevented, for an unevenly protected or covered surface will promote a localization of disturbing agencies, and especially in treacherous ground when it has been covered, neither the surface nor the turf should be allowed to be broken. In ordinary cases where slips may be expected, soiling with mould or top dressing, and sowing the slopes may be sufficient, and turfing in others of small extent; but in retentive soluble soil, a filtering layer under the turf may be required, so as to prevent spreading, particularly near the toe of a slope; however, in mountainous or hilly districts, experience seems to indicate that it is advisable to allow earthwork to become consolidated by the natural effect of rain and atmosphere before finally trimming or covering the slopes: on the contrary it may be advisable, especially in treacherous ground, to trim and cover with mould, sow, turf, plant, or cover the slopes as soon as possible after they are excavated or deposited, in order to protect soluble soil from rain, frost, or snowstorms consequent upon the wet season being near. Of course, when experience shows that slips are improbable, the slopes can remain bare and simply be trimmed, and a covering of grass be left to time to effect, and this is now the frequent practice. Should settlement be expected or be unavoidable, the face protection can be so made that it will not be disturbed or broken. In such a case a short, straight slope with a flat inclined berm or cess, the length of the slope being divided into three or four short continuous straight portions, has been adopted with success. Should sowing or planting the slopes be considered as too slow in producing a covering, experiments can be made by mixing available soils, or with one earth; and by exposing the mixture or earth to the deteriorating weather influences it will have to resist, the best