Such partitions as are required for the divisions in ordinary houses are usually formed by timber of small size, termed studs or joists. These are placed upright at 12 or 16 inches from centres, and well nailed. Upon these studs lath are nailed, and these are covered with plastering. The strength of the plastering depends in a great measure upon the clinch formed by the mortar which has been pressed through between the lath. That this clinch may be interfered with in the least possible degree, it is proper that the edges of the partition-joists which are presented to receive the lath should be as narrow as practicable; those which are necessarily large should be reduced by chamfering the corners. The derangements in floors, plastering, and doors which too frequently disfigure the interior of pretentious houses with gaping cracks in the plastering and in the door-casings are due in nearly all cases to defective partitions, and to the shrinkage of floor-timbers. A plastered partition is too heavy to be trusted upon an ordinary tier of beams, unless so braced as to prevent its weight from pressing upon the beams. This precaution becomes especially important when, in addition to its own weight, the partition serves as a girder to carry the weight of the floor-beams next above it. In order to reduce to the smallest practicable degree the derangements named, it is important that the studs in a partition should be trussed or braced so as to throw the weight upon firmly sustained points in the construction beneath, and that the timber in both partitions and floors should be well seasoned and carefully framed. To avoid the settlement due to the shrinkage of a tier of beams, it is important, in a partition standing over one in the story below or over a girder, that the studs pass between the beams to the plate of the lower partition, or to the girder; and, to be able to do this, it is also important to arrange the partitions of the several stories vertically over each other. All principal partitions should be of brick, especially such as are required to assist in sustaining the floors of the building.