Rate of Work.—“In one single day three courses of about 3 ft. each may be laid one over the other; so that a wall of earth of about 8 or 9 ft., or one story high, may be safely raised in one day. Experience has proved that as soon as the builders have raised their walls to a proper height for flooring, the heaviest beams and rafters may without danger be placed on the walls thus newly made; and that the thickest timber of a roof may be laid on the gables of pisé the very instant they are completed.”
Suitable Soils
ON EARTH PROPER FOR BUILDING
Suitable Soils.—“1st. All earths in general are fit for that use, when they have not the lightness of poor lands nor the stiffness of clay.
“2ndly. All earths fit for vegetation.
“3rdly. Brick-earths; but these, if they are used alone, are apt to crack, owing to the quantity of moisture which they contain. This, however, does not hinder persons who understand the business from using them to a good purpose.
“4thly. Strong earths, with a mixture of small gravel, which for that reason cannot serve for making either bricks, tiles, or pottery. These gravelly earths are very useful, and the best pisé is made of them.”
Soil Tests.—“The following appearances indicate that the earth in which they are found is fit for building: when a pickaxe, spade, or plough brings up large lumps of earth at a time; when arable lands lies in clods or lumps; when field-mice have made themselves subterraneous passages in the earth; all these are favourable signs. When the roads of a village, having been worn away by the water continually running through them, are lower than the other lands, and the sides of those roads support themselves almost upright, it is a sure mark that pisé may be executed in that village. One may also discover the fitness of the soil by trying to break with one’s fingers the little clods of earth in the roads, and finding a difficulty in doing it; or by observing the ruts of the road, in which the cart-wheels make a sort of pisé by their pressure; whenever there are deep ruts on a road, one may be sure of finding abundance of proper earth.
“Proper earth is found at the bottom of the slopes of low lands that are cultivated, because every year the rain brings down the fat or good earth. It is frequently found on the banks of the river, but above all, it is found at the foot of hills, and on all cultivated lands which have much slope. In digging trenches and cellars for building, it generally happens that what comes out of them is fit for the purpose.”