If the disfigurement of the door-frame between two rooms, or room and hallway, is a serious objection, the jambs of a roomy closet door may be used, in which case the closing of the door shuts the holes from sight. Two high tables, or a foot rail of a bed and a table, or box placed firmly upon two chairs--in short, any two pieces that will afford a lift of the body, such as that described, will serve the purpose nearly as well. =Door-Jamb Exercise, No. 3.=--By fastening two cleats or supports on the inner faces of the door-frame, with a niche or slot in each, to support a horizontal bar, extending across the doorway near the top, just within reach, a simple but very valuable piece of apparatus is ready for use. For strengthening the fingers and the grasp of the hands, as in swinging back and forth by the arms, and in developing certain arm, back, and abdominal muscles, as in lifting the body so as to touch the chin to the bar, few exercises are better. The latter was a favorite exercise of William Cullen Bryant, and one to which he attached much value. It is attended with some danger, however, and should not be attempted without preparatory drill. The sides of the bar, at the ends where it enters the cleats, should be slightly flattened, so as not to turn with the swinging motion of the body. Two or three sets of cleats may be used, adapting the height to different members of the family. REST =Its Necessity.=--Rest is as necessary as exercise. We cannot be active continually. Repose must succeed labor. Alfred the Great is credited with the recommendation that each day be divided into three parts, eight hours for labor, eight hours for recreation, and eight hours for sleep. =Change of Employment.=--A change of occupation affords rest. The wood chopper finds relief from his ax by using his saw. A different set of muscles is brought into play. Persons might often save themselves from excessive fatigue by the adoption of this principle. When physical labor is made to alternate with mental activity, the sense of rest is more apparent. =Sleep.=--The best form of rest is found in sleep. All voluntary activity then ceases. Even the involuntary processes of circulation and respiration seem to share in the general restfulness, for during sleep their action is more tardy, and, as a result, the temperature of the body is somewhat lower. More covering is needed during sleep than during the waking hours. While the body is in action, the process of pulling down predominates, but during sleep nutrition goes on, the wasted tissues are built up, and we rise refreshed and prepared for the new day’s duties. =Amount of Sleep.=--All persons do not require the same amount of sleep. It is said that Frederick the Great slept only five hours each night. Napoleon Bonaparte could pass days with only a few hours’ rest. Persons whose labors are mental require more sleep than those who work with their hands.