Whereas women don’t breathe so much of what is noxious yet they have to look after their men folk! But joking aside, doesn’t this impress you with the foolishness of inhaling so much vitiated air when the supply can be renewed so easily with fresh air? Also when you realize that humans give off 1000 grams of water vapor under normal conditions per hour, and emit 350 British Thermal Units per hour. (A B. T. U. is the amount of heat which will raise 1 pound of water 1° Fahrenheit or from 32° thru 33° of heat--at normal, not heavy work.) Another authority says that air should be renewed per hour: 10 times for public toilet rooms. 6 “ “ clothes lockers. 4 “ “ small meeting rooms. 5 “ “ public offices. 4 “ “ ball rooms. 15 “ “ kitchens. 20 “ “ laundries. 3 “ “ libraries. The average air change in the average room is one to two times per hour. In the well-built house it is two to three--due to fire-places, windows, doors, etc. Of course there are other opinions, but this data gives you an idea of the necessity of changing old for new air. [Illustration: _Courtesy of Ilg Electric Ventilating Co._ SHE IS COOL EVEN IN SUMMER WITH MOVING AIR] GOOD VENTILATION The requisites then for good ventilation are: 1. Equable temperature from about 60 to 65 degrees Fahrenheit, and the moderate relative humidity or moisture of 45 to 65 per cent. In order to keep the room moist in winter it is well to keep a pan of water on the radiator. Regular humidifyers can be bought for this purpose. 2. Clear air, free from impurities such as dust, insects, oily vapors, soot, etc. 3. Odorless air (you have been sickened by the use even of the most costly of perfumes!) free from gases and vapors. 4. Air motion; but the motion must be accomplished without those objectionable blasts of wind that so frequently startle you in some houses which are supposed to have the most up to date equipment. The weather strip is insurance against the gale. Air isn’t a mysterious chemical combination. It is a mechanical mixture of 21 parts nitrogen, 79 parts of oxygen, from 0 to 4% of moisture, and usually 4 parts of carbon dioxide gas per 10,000 parts of air, so it need not distress you to effect a good clean supply of air and equip your house with some of the steadily improving devices now on the market. SOME DEVICES Any device to be useful to the home must, of course, be convenient, economical, safe to operate, and durable. Well, let’s begin with the kitchen; for this ventilation is more necessary than any place else in the house.