The temperature is a matter of importance. It should not be decided by guess-work, but a thermometer should be hung upon a wall at a place equally removed from draft and from the source of heat. The temperature for children during the first year should be about 70 degrees Fahrenheit during the day and not lower than 50 degrees at night. Children who sleep with the mother will not be injured by a temperature 5 to 20 degrees lower at night. [Sidenote: Fresh Air] It is important to provide means for the ingress of fresh air. It is not sufficient to air the room from another room unless that other room has in it an open window. Even then the nursery windows should be opened wide from fifteen minutes to half an hour night and morning, while the child is in another room; and this even when the weather is at zero or below. It does not take long to warm up room that has been aired. Perhaps the best means of obtaining the ingress of fresh air without creating a draft upon the floor, where the baby spends so much of his time, is to raise the window six inches at the top or bottom and insert a board cut to fit the aperture. [Sidenote: Daily Outing] But no matter how well ventilated the nursery may be, all children more than six weeks old need unmodified outside air, and need it every day, no matter what the weather, unless they are sick. The daily outing secures them better appetites, quiet sleep, and calmer nerves. Let them be properly clothed and protected in their carriages, and all weathers are good for them. Children who take their naps in their baby-carriages may with advantage be wheeled into a sheltered spot, covered warmly, and left to sleep in the outer air. They are likely to sleep longer than in the house, and find more refreshment in their sleep. SUFFICIENT SLEEP. Few children in America get as much sleep as they really need. Preyer gives the record of his own child, and the hours which this child found necessary for his sleep and growth may be taken for a standard. In the first month, sixteen, in full, out of twenty-four hours were spent in sleep. The sleep rarely lasted beyond two hours at a time. In the second month about the same amount was spent in sleep, which lasted from three to six hours at a time. In the sixth month, it lasted from six to eight hours at a time, and began to diminish to fifteen hours in the twenty-four. In the thirteenth month, fourteen hours' sleep daily; it the seventeenth, prolonged sleep began, ten hours without interruption; in the twentieth, prolonged sleep became habitual, and sleep in the day-time was reduced to two hours. In the third year, the night sleep lasted regularly from eleven to twelve hours, and sleep in the daytime was no longer required. [Sidenote: Naps]