In case open Franklin stoves are used in the large rooms, the pure air from the conductor should enter behind them, and thus be partially warmed. The vitiated air is carried off at the bottom of the room through the open stoves, and also at the top by a register opening into a conductor to the exhausting warm-air shaft, which, it will be remembered, is the square chimney, containing the iron pipe which receives the kitchen stove-pipe. The stove-room receives pure air from the conductor, and sends off impure air and the smells of cooking by a register opening directly into the exhausting shaft; while its hot air and smoke, passing through the iron pipe, heat the air of the shaft, and produce the exhausting current. The construction of the exhausting or warm-air shaft is described on page 63.
The large chambers on the second floor (Fig. 12) have pure air conducted from the stove-room through registers that can be closed if the heat or smells of cooking are unpleasant. The air in the stove-room will always be moist from the water of the stove boiler,
The small chambers have pure air admitted from windows sunk at top half an inch; and the warm, vitiated air is conducted by a register in the ceiling which opens into a conductor to the exhausting warm-air shaft at the centre of the house, as shown in Fig. 17.
The basement or cellar is ventilated by an opening into the exhausting air shaft, to remove impure air, and a small opening over each glazed door to admit pure air. The doors open out into a "well," or recess, excavated in the earth before the cellar, for the admission of light and air, neatly bricked up and whitewashed. The doors are to be made entirely of strong, thick glass sashes, and this will give light enough for laundry work; the tubs and ironing-table being placed close to the glazed door. The floor must be plastered with water-lime, and the walls and ceiling be whitewashed, which will add reflected light to the room. There will thus be no need of other windows, and the house need not be raised above the ground. Several cottages have been built thus, so that the ground floors and conservatories are nearly on the same level; and all agree that they are pleasanter than when raised higher.
When a window in any room is sunk at the top, it should have a narrow shelf in front inclined to the opening, so as to keep out the rain. In small chambers for one person, an inch opening is sufficient, and in larger rooms for two persons, a two-inch opening is needed. The openings into the exhausting air flue should vary from eight inches to twelve inches square, or more, according to the number of persons who are to sleep in the room.
The time when ventilation is most difficult is the medium weather in spring and fall, when the air, though damp, is similar in temperature outside and in. Then the warm-air flue is indispensable to proper ventilation. This is especially needed in a room used for school or church purposes.
Every room used for large numbers should have its air regulated not only as to its warmth and purity, but also as to its supply of moisture; and for this purpose will be found very convenient the instrument called the Hygrodeik, [Footnote: It is manufactured by N. M. Lowe, Boston, and sold by him: and J. Queen & Co., Philadelphia.] which shows at once the temperature and the moisture. A work by Dr. Derby on Anthracite Coal, scientific men say has done much mischief by an unproved theory that the discomfort of furnace heat is caused by the passage of carbonic oxide through the iron of the furnace heaters, and not by want of moisture. God made the air right, and taking out its moisture must be wrong.
The preceding remarks illustrate the advantages of the cottage plan in respect to ventilation. The economy of the mode of warming next demands attention. In the first place, it should be noted that the chimney being at the centre of the house, no heat is lost by its radiation through outside walls into open air, as is the case with all fireplaces and grates that have their backs and flues joined to an outside wall.
In this plan, all the radiated heat from the stove serves to warm the walls of adjacent rooms in cold weather; while in the warm season, the non-conducting summer casings of the stove send all the heat not used in cooking either into the exhausting warm-air shaft or into the central cast-iron pipe. In addition to this, the sliding doors of the stove-room (which should be only six feet high, meeting the partition coming from the ceiling) can be opened in cool days, and then the heat from the stove would temper the rooms each side of the kitchen. In hot weather, they could be kept closed except when the stove is used, and then opened only for a short time. The Franklin stoves in the large room would give the radiating warmth and cheerful blaze of an open fire, while radiating heat also from all their surfaces. In cold weather, the air of the larger chambers could be tempered by registers admitting warm air from the stove-room, which would always be sufficiently moistened by evaporation from the stationary boiler. The conservatories in winter, protected from frost by double sashes, would contribute agreeable moisture to the larger rooms. In case the size of a family required more rooms, another story could be ventilated and warmed by the same mode, with little additional expense.
We will next notice the economy of time, labor, and expense secured by this cottage plan. The laundry work being done in the basement, all the cooking, dish-washing, etc., can be done in the kitchen and stove-room on the ground floor. But in case a larger kitchen is needed, the lounges can be put in the front part of the large room, and the movable screen placed so as to give a work-room adjacent to the kitchen, and the front side of the same be used for the eating-room. Where the movable screen is used, the floor should be oiled wood. A square piece of carpet can be put in the centre of the front part of the room, to keep the feet warm when sitting around the table, and small rugs can be placed before the lounges or other sitting-places, for the same purpose.