"When manure is placed together in large piles it immediately commences to ferment. This fermentation is needed to put the manure into a proper condition for the mushroom spawn. But, it must be regulated and controlled, or the violent heat would destroy the elements needed for the mushroom's growth. ...If the manure is dry it should be moistened. Just enough water should be used so that when the manure is ready to go into the mushroom house no water can be squeezed out, if a portion is wrung or twisted tightly in the hands. After the manure has been moistened and piled it should be covered with three inches of good soil. ...If it is hot and there are any particles in the center that show evidence of "fire-fanging" it should be turned immediately. Fire fanging is characterized by the strawy particles having a white mouldy appearance. ...At the same time the soil that was spread over the pile should be spread and mixed all through the manure. After a day or two the pile should again be turned. This turning process should be repeated until all the particles have become of a rich coffee-brown color. This will be a week or ten days after the manure is collected, depending upon the season of the year. When the condition of the manure has arrived at this stage no time should be lost in getting it into the beds. Care should be taken in placing the prepared manure on the shelves or beds, that it is spread smoothly and evenly and well packed down. Not less than eight inches and not more than twelve inches will be found the right depth, under ordinary circumstances, for the manure on the shelves or beds."