The lowest floor, should lie sufficiently elevated above the earth to prevent damp, and to facilitate carting. Experience has proved that a height of 8 feet is sufficient fm. the curve that is described by the wheat when thrown up by a shovel. Each floor should therefore have a height of 10 feet.
The walls of the granary should be thick, not only on account of strength, but also to keep out damp and heat. The windows should descend to the level of the floor, so that the air may circulate through the lowest part, and strike the foot of the heap of grain. The entrance of the air is fa•ili tated by widening the openings from the interior to the exterior. They should be grated with iron wire to prevent the entrance of birds, and furnished with shutters which, when open, fall back on the thickness of the wall.
When the granary is of considerable size, it appears natural to place the entrance in the middle of its length. This entrance should be large enough to permit vehicles to cross the building, so as to load or unload under cover. To prevent the division of the lowest floor, this passage is some times made by a projecting porch, under which the vehicles can be ranged, though in a less convenient manner. The staircases should be placed, near the passage, for the carts, but, to prevent interruption of the heaps of corn. some place them in a projection opposite the porch, or in one of the angles of the building.
It is desirable that granaries should not he of too great an extent, in order that the grain may more readily dry by the currents of air. On the other hand, as it is always necessary to reserve the passages along the walls, the size of the interior should not he less than 40 feet, or exceed 65 feet. In all
cases, they are divided by pillars of stone, wood, or cast iron. (Braiere Etudes Relatives a Cart des Constructions.) The following may be taken as a guide for the erection of a granary in this country. The building should be rectangular in plan, the height about twice the distance between the opposite walls, that is, 20 feet high by 10 feet in width on each side, and provided with ninnerous air-holes, declining out. wards, to prevent the entrance of rain or snow. From each air-hole to a corresponding one on the opposite side, should be fixed an inverted angular spout or glitter, to permit the air to pass through unimpeded by the corn lying about ; as many of these glitters should be fixed, as there are holes to receive the ends after crossing the building ; and the extremities of the holes should be covered with wire gauze, to defend them from vermin.
The first floor of the granary should be divided into a series of hoppers, these hoppers to empty themselves into one large hopper underneath. provided with a sliding door to regulate the passage of the grain into a sack or other recep tacle. At the top of the building a loft should be erected, to which the corn may be first hoisted by a tackle or crane, and he discharged over across-bar into the body of the building, which operation may be continued until it is filled to the top. Upon drawing off any corn at the bottom, the whole of it will be put in motion, and the airing of every part promoted ; the process of airing should, however, be continually going forward through the numerous passages under the inverted gutters, the angles of which do not fill up by the lateral pressure of the grain.