The foregoing cause of the evil being understood, it is also plain that any arrangement which will render the temperature of the air the same on both sides of the pane will remedy the difficulty. Any other method is obviously imperfect and ineffectual. If the temperature within and without the window is the same the glass cannot sweat or frost.
To obtain an even temperature it is absolutely necessary to box the window. It must be cut off entirely from the other part of the store.
FIG. 1.
The space under modern show windows is used largely for ventilating cellars. Our sketch shows half of this space used for ventilating cellar, and other half as a cold air passage to allow the outside air to pass through the double perforated window floor, thereby keeping the air within the window enclosure approximately the same temperature as the outside, and thereby preventing the sweating and freezing, so annoying to the trimmer.
FIG. 2.
A A, open space between double perforated bottom, to be filled with loose cotton to permit the air to pass, but dense enough to keep back the dust from the street.
The floor of the window should be made of boards, perforated and made to fit in snugly without fastening down, so they can be taken up occasionally to clean out the dust that will accumulate in time.
