Fig. 3. Cross-section of the Dosoris Mushroom Cellar.
The Dosoris Mushroom Cellar.—This is a subterranean tunnel or cellar that was excavated and arched some ten years ago, expressly for the cultivation of mushrooms. It is situated in an open, sunny part of the garden, and its extreme length from outside of end walls is eighty-three feet; but of this space nine feet at either end are given up to entrance pits and a heating apparatus; and the full length of the mushroom cellar proper inside the inner walls is sixty-three feet. The walls and arch are of brick, and the top of the arch is two and one-half feet below the surface of the soil. This tunnel or arch is seven feet high in the middle and eight feet wide within, but a raised two-feet-wide pathway along the middle lessens the height to six and one-half feet. Between this pathway and the sides of the building there is only an earthen floor, but it is quite dry, as the cellar is perfectly drained. Three ventilators sixteen feet apart had been built in the top of the arch, but this was a mistake, as the condensation in the cellar in winter from these ventilators always keeps the place under them cold and wet and rather unproductive. One tall wooden chimney-like shaft would have been a better ventilator than the three ventilating holes now there, which are covered over with an iron and glass grating.
Fig. 4. Ground Plan of the Dosoris Cellar.
At one end of the house and behind the stairs descending into the pit is the heating apparatus, from which a four-inch hot-water pipe passes around inside the house near the wall and only four inches above ground. A three-feet wide hemlock flooring for the bed to rest on is laid along each side and about four inches above the pipe, leaving the aperture between the earth floor and the bottom of the bed along the pathway open for the escape of the artificial heat. One might think that the hot water pipe under, and so near the bed, would dry it up and destroy it, but such is not the case. In a cellar of this kind very little fire heat is needed to maintain the required temperature, and I do not know where else the pipes could be put where they would do the work any better and be more out of the way.
These beds, for convenience in building them, spawning them, molding them over, gathering the crop and watering the beds, and removing the manure after the beds are exhausted, are built against the wall and with a rounded face, thus giving a three and one-half feet wide surface of bed in place of one three feet wide, were it built flat. This gain in superficial area is not so important as it might seem, for the part immediately next to the edge of the pathway seldom yields very much. Above these beds a string of shelf beds is arranged which runs the full length of both sides of the cellar. From the floor of the under bed to the floor of the top bed is three feet, and the upper beds are just as wide as the lower ones. The shelves for the beds are temporary affairs, put up and taken down every year. The cross-bars rest in sockets in the wall made by cutting out half a brick every four feet along the wall, and on upright strips or feet one and one-fourth by four inches wide, or two by three inches, set under the inside ends of the cross-bars and resting on the cement floor close up against the lower bed. By having this foot end a quarter of an inch higher than the wall end the heavy weight of the bed is thrown toward the wall. Loose hemlock boards set close together form the flooring, for there is no need of nailing any of them except the one next to the upright face board, which is ten inches wide, and nailed along the front, by the pathway, to the posts and shelf board. By tilting the weight to the wall the upright board is firm enough to hold its place against any pressing out in building the beds. The supporting legs of the shelves are also nailed to the face board of the lower bed, and this holds them perfectly solid in place. The shelf beds are eight inches deep at front, but can be made of any depth desired against the walls at the back. The cold wall has no injurious effect upon the bearing of the bed, and many fine mushrooms grow close against the walls.
The entrance pits are nine and one-half feet deep from ground level, three feet eight inches wide, nine feet long, and are covered over with folding doors on strong hinges, and descended into by means of wooden movable stairs. These dimensions are needed at the end where the heating apparatus is placed, but at the other end, although it is convenient in handling the manure, a space two or three feet less would have answered just as well. A close door at either end of the mushroom cellar proper separates it from the end pits. The cellar is divided in the middle by a partition. This gives, when it is in full working order, eight beds, each thirty-one and one-half feet long, or a continuous run of 252 feet or 756 square feet of surface, and as the beds are renewed twice a year this gives 504 running feet of bed, or 1512 square feet of surface. A common average crop is three-fifths of a pound of mushrooms to the square foot of bed, and a good fair average is four-fifths of a pound. This would give over a thousand pounds of mushrooms a season from this cellar when it is in full running capacity. But as the aim is to have a steady supply of mushrooms from October until May, and not a flush at any one time and a scarcity at another, only two beds are made at a time, allowing a month to intervene between every two.
For the two beds, No. 1, preparing the manure begins in July, the beds are made up in August, and gathering of the crop commences in October; work on the two beds, No. 2, begins in August, the beds are made up in September, and the mushrooms gathered in November; preparing for the two beds, No. 3, begins in September, the beds are made up in October, gathering commences in December; for the two beds, No. 4, work begins in October, the beds are made up in November, and the crop is gathered in January; for the two beds, No. 5 (No. 1 renewed), work begins in November, the beds are made up in December, and the crop is gathered in February; for the two beds, No. 6 (No. 2 renewed), work begins in December, the beds are made up in January, and the crop is gathered in March; for the two beds, No. 7 (No. 3 renewed), work begins in January, the beds are made up in February, and the crop is gathered in April; for the two beds, No. 8 (No. 4 renewed), work begins in February, the beds are made up in March, and the mushrooms gathered in May. After this time of year the summer heat renders mushroom-growing uncertain, and the maggots destroy the mushrooms. This system allows each bed a bearing period of two months. After yielding a crop for some seven to nine weeks the beds are pretty well exhausted and hardly worth retaining longer. They might drag along in a desultory way for weeks, but as soon as they stop yielding a paying crop we clear them out and start afresh.