Keeping the room as air-tight as possible tends to preserve the ice. Whenever the house is opened the warm air enters, and vapor will collect above the ice. This should be given an opportunity to escape, by opening the ventilator doors in the loft floor.
FIG. 54. HOUSE ICE SAW.
FIG. 55. RAISING CHISEL BAR.
FIG. 56. STRIKING-UNDER BAR.
FIG. 57. DUNNAGE SHOVEL.
As the ice is taken from the house, the covering of sawdust should be kept in place over the ice as far as possible. If the space over the ice is sealed up, the air, being above the freezing point, becomes saturated with moisture, which settles upon the ice, softening and melting it. When the outside air is cooler than that over the ice or in the loft, the moist air is driven out, if the ventilators are open. Hence, in clear weather, the ventilators should be opened at night. In foggy or damp weather, ventilators should be kept closed.