"Not liking to entrust my chance of mushrooms entirely to the new material, the French spawn, two beds were spawned at the same time and in the same manner with native spawn. Owing to the large size of the stable, and the unusually cold, piercing weather at the end of the year (1869), the beds lost so much heat that I had some misgivings whether they would not prove a failure; but finding, subsequently, that the spawn was working, I gave each bed (the surface being rather dry) a good syringing with water at the temperature of 80 deg., covered it with clean dry mats, and then returned the hay. The beds are now a sheet of the 'pearl of the fields,' some of the patches as large as a cheese-plate, and the whole in most promising condition--so promising that, with proper attention, I have no doubt they will yield a good supply of mushrooms for many months. To secure this continuous bearing, farmyard manure-water and salt, at proper times, should not be spared; while, as soon as the flush of the first crop is over, the beds may receive a thorough soaking of manure-water at a temperature of not less than 80 deg., be re-earthed with fresh soil, and covered down with mats and hay. In this manner we always get a second crop little inferior to the first one, and sometimes much superior."
THE temperature of the material of the beds should never, at spawning time, exceed 80 degrees Fahr.--about 70 is the most suitable regular temperature; and that of the mushroom-house should range between 50 and 60 degrees--not lower than 50. Assuming the materials to have been turned once after having heated, and again disturbed previous to being made into beds, they ought to be in a condition for spawning from ten to twelve days after being put together. It need hardly be said that this regularity of temperature can only be secured in properly-formed mushroom-houses. Where mushrooms are grown in these, with double ceilings and close-fitting shutters and doors, almost impervious to external influences, and where fresh beds are made from time to time, little or no artificial heat from pipes is required, though it is as well to have some at command in the case of unusually severe weather, or a break in the succession of beds, which would cause a deficiency of heat from fermenting materials. A covering of hay or dry litter is necessary for beds formed in the open air, and also for beds made in cool, half-open sheds; but not for those in regularly heated mushroom-houses or caves, in which there is a still, steady temperature. It should be about a foot thick, and should be immediately removed when it becomes wet or mouldy. This covering should be applied whenever the temperature of the bed begins to fall. It should not be used in any case where the temperature will permit of dispensing with it, as it is troublesome, and sometimes encourages insects. The heat of a bed may be reduced by opening holes six or eight inches deep with a thick pointed dibber, here and there, but it is only in exceptional cases that this is advisable, and it is desirable to husband all the ammonia and heat of the bed. The earthing over and firming of a bed has a tendency to subdue the heat in it. Where large sloping beds, say three feet deep at back, are made against the wall, I have seen [V]-shaped crates put beneath them at six feet apart, so as to permit of heating them by fresh supplies of manure. It is, however, a plan possessing little claim to general use. It is best not to depend on the hand, as is commonly done, for ascertaining the heat of the beds. Thermometers fixed on sticks of convenient size, to thrust in the beds, are sold, and remove all excuse for vagueness in this matter. Coverings of litter are sometimes useful in "drawing-up the heat" in a bed that has become somewhat chilled.