No arrangement of windows, however perfect, is likely to remain satisfactory for more than an hour at a time, except in warm weather. This watchfulness and attention takes time, but it is time well spent. "Eternal vigilance" is the price of good ventilation, as well as of liberty; and you will get far more work done in the course of a morning by interrupting it occasionally to go and raise or lower a window, than you will by sitting still and slaving in a stuffy, ill-smelling room. Plenty of Heat Needed. Any method of heating--open fireplace, stove, hot air, furnace, hot water, or steam--which will keep a room _with the windows open_ comfortably warm in cold weather is satisfactory and healthful. The worst fault, from a sanitary point of view, that a heating system can have is that it does not give enough warmth, so that you are compelled to keep the windows shut. Too little heat is often as dangerous as too much; for you will insist on keeping warm, no matter what it may cost you in the future, and a cold room usually means hermetically sealed windows. Remember that coal is cheaper than colds, to say nothing of consumption and pneumonia. [Illustration: A HEALTHFUL BEDROOM Windows on two sides; shades rolling from the middle; draperies few and washable; no carpet, but rugs by the bedside.] Ventilating the Bedroom. The same principles that apply to ventilating a living-room or day-room apply to ventilating a bedroom. Here you can almost disregard drafts, except in the very coldest weather, and, by putting on plenty of covering, sleep three hundred days out of the year with your windows wide open and your room within ten degrees of the temperature outdoors. You need not be afraid of catching cold. On the contrary, by sleeping in a room like this you will escape three out of four colds that you usually catch. Sleeping with the windows wide open is the method we now use to cure consumption, and it is equally good to prevent it. No bedroom window ought to be closed at the top, except when necessary to keep rain or snow from driving in. Close the windows for a short time before going to bed, and again before rising in the morning, to warm up the room to undress and dress in; or have a small inside dressing-room, with your bed out on a screened balcony or porch. But sleep at least three hundred nights of the year with the free air of heaven blowing across your face. You will soon feel that you cannot sleep without it. In winter, have a light-weight warm comforter and enough warm, but light, blankets on your bed, and leave the heat on in the room, if necessary--but _open the windows_. COLDS, CONSUMPTION, AND PNEUMONIA