And when the mushroom season is closed we lift out and remove the manure, clean the boards used in shelving, and give the cellar a thorough cleaning,—whitewash its walls and paint its woodwork with kerosene to destroy noxious insects and fungi.
Fig. 5. Base-burning Water Heater.
Fig. 6. Vertical Section.
The heating apparatus consists of one of Hitchings' base-burner boilers with a four-inch hot-water pipe that passes around inside the cellar, and it deserves special mention because of its economy, efficiency, and the satisfaction it gives generally. This boiler needs no deep or spacious stoke-hole. Here it is set under the stairway in a pit four and one-half feet long, by three feet wide, by eighteen inches deep; it is not in the way, and there is plenty of room to attend to it. The heater, like a common parlor stove, has a magazine for the supply of coal. It has a double casing with the water space between and down to the bottom of it, so that when set in a shallow pit there is no difficulty whatever about the circulation of the water in the pipes. The hot water passes from the boiler to an open iron tank placed two feet above it, as shown in the engraving, and thence down through a perpendicular pipe till it reaches and enters the horizontal pipes that pass around the cellar and, returning, enters the boiler again near its base. The boiler and pipes are filled from this tank, which should always be kept at least half full of water, and looked into every day when in use, so that when the water gets lower than half full it may be filled up again. About 134 running feet of four-inch pipe are included inside the cellar (sixty-four feet on each side and six feet across at further end); this gives 134 square feet of heating surface, or a proportion of about a square foot of heating surface for every fifteen cubic feet of air space in the cellar. This proportion is more than ample in the coldest weather, but beneficial in so far that there is no need to fire hard to maintain the proper temperature. A three-inch pipe would have given heat enough, but the heat would not have been so steady. Both nut and stove coal is used in this heater, and in the severest winter weather it burns not more than a common hodful in twenty-four hours. It is so easily regulated that the temperature of the cellar day or night, or in mild or severe weather, never varies more than three degrees, namely from 57° to 60°.
In a close underground cellar where the temperature in midwinter without any artificial heat does not fall below 40° or 45° it is an easy matter, with such a heater as this is, to maintain any desired temperature. If the grates are renewed now and then, the heater should last in good condition for twenty years. With the ordinary stove there is danger of fire, of escaping gas and of sudden changes of temperature, and the evil influence of a dry, parching heat—just what mushrooms most dislike—is ever present. The first cost of a hot water apparatus may be more than that of an old stove and sheet iron pipes, but where mushrooms are grown extensively, as a matter of economy, efficiency, and convenience, the advantages are altogether on the side of the hot water apparatus. Furthermore, hot water pipes can be run where it would be unsafe to put smoke pipes.