GROWING MUSHROOMS IK CELLARS. 
33 
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 cel¬ 
lar 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 sud¬ 
den 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 appa¬ 
ratus 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. 
