This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
As the season for these approaches, I beg to suggest the use of water ones to gardeners. Dung hot beds are troublesome, especially those required in action for a length of time, as fruiting beds for melons, cucumbers, tomatoes, etc.,. I think the double arrangement best, as it possesses the advantage of being workable in all kinds of weather. The spaces, d, of course need not be excavated unless desired; but I think it best to do so; they can be used for growing mushrooms, sea kale, rhubarb, or asparagus, without bottom heat; or, by running the return pipe around again, can be turned into forcing beds for the same.
A Board bottom supported upon Joist upright* and cross pleces.
There should be slides in the edge of the heating chamber c, to open at night or in bad weather, to equalize the top and bottom heat.
[The above suggestion is a good one. We have put up and are putting up hot-beds on about the same principle, the difference consisting chiefly in the mode of heating; and in this respect the difference is small. To those who can afford the first cost, the arrangement is a good one, and will prove satisfactory. To others, we recommend the excellent plan of making hot-beds described elsewhere by a "Jersey Market Gardener." - Ed].