After the beds are made up they should be covered and allowed to heat for a week or ten days. After this length of time the temperature should be watched until it falls to 70 degrees, when the beds may safely be spawned. The temperature may be obtained by inserting a common glass thermometer in the manure. During the process of heating, after the beds are made up, the temperature often rises as high as 125 degrees, and it is never safe to spawn until it falls to 70 degrees. [Illustration: _The above illustration shows how an ordinary cellar may be fitted up either with beds on the floor or arranged in tiers, one above the other, in order to increase the growing surface._] =SPAWNING= The bricks of spawn should be broken into ten or twelve pieces and placed on the surface of the beds 8 to 10 inches apart each way. Then go over the bed again, raising the manure and burying the spawn about half-inch below the surface and tamping (pressing) firmly over each piece, leaving the bed level on top. In about two weeks dig up a piece or two of spawn carefully, and if the mycelium is noticed running out like a mould from the brick into the manure it is time to case. This is done by putting one inch of sifted soil evenly over the top of the manure. =VENTILATION= Where mushrooms are grown on a large scale, proper ventilation is very necessary. The overhead ventilators are generally preferred, as the ventilation is more uniform without draught. The ventilators should remain open when outside temperature is right, and at other times for one or two hours each day. Where small beds are used in cellars or out-buildings, extra ventilation is not so necessary. AVOID ALL DRAUGHTS. =WATERING= While the room should be kept moist, little or no water should be used on the beds after spawning till the mushrooms begin to appear, which is generally from six to eight weeks from time of spawning. Then the beds at first should be sprinkled lightly every day or two till the surface is quite moist, after that one or two sprinklings a week will be sufficient, according to the condition of the beds. If they get dry quickly water oftener. [Illustration: _Mushroom Growing Plant No. 2, built and operated by Edward H. Jacob, West Chester, Pa. This plant contains eleven separate Mushroom houses, with a total growing surface of 78,500 square feet; each building is 100 feet long._] PICKING The mushrooms should be picked once a day just before they open out. (_See cut._) The root should be twisted gently and taken out with the mushroom disturbing the earth as little as possible. The stems should be cut off and the mushrooms packed in baskets. When grown in small quantities, the 1-pound ventilated boxes are often used as a matter of convenience, but the large growers ship generally in four-pound baskets. (_See cut._)