Woodward's Graperies and Horticultural Buildings

by George E. Woodward; F. W. Woodward

Hot Water Pipes.—It is generally conceded, among practical men, that the circulation of hot water in iron pipes is the best known method of heating plant houses. The property which heated water possesses of retaining for a considerable length of time its heat and transmitting it to the pipes at long distances from the boiler, renders it a most effective agency for such purposes: A perfect control of the moisture of the atmosphere, by means of evaporating pans attached to the pipes; entire freedom from deleterious gases, sometimes escaping from flues, and the substantial character and enduring qualities of the apparatus, are important considerations in favor of this method of heating which are not to be overlooked or underrated.

It is true that a house of a given size cannot as soon be brought to the required temperature after the fire is first lighted, as by other modes of heating, but when once in full operation greater regularity is maintained, and if the fire should by any neglect go out, heat is still radiated, often for several hours, before the pipes become entirely cold.

For heating ornamental houses of glass, pipes are also to be recommended on account of the little room they occupy and the neatness of their appearance compared with the unsightly flues or tank. If properly put up, the pipes never leak at the joints, as is the case frequently with tanks, and scarcely need any repairs for years. The first cost of apparatus for heating by hot water pipes exceeds that of the other methods which we have named, but when we take into account its great durability, economy of fuel, and the satisfactory results produced in the growth of plants in houses heated in this manner, it must be evident that this method is the cheapest in the end.

It is generally supposed that the heat obtained from steam or hot water pipes necessarily contains moisture. For those who have had any experience in the use of these methods of heating, it is needless to say that such is not the case. To obtain moisture evaporation of water in some manner in the atmosphere must be effected. This is provided for by attaching to the pipes evaporating pans filled with water, by which the moisture can be perfectly regulated and controlled. The capacity of the boiler and the length of the pipes should be in proportion to the size of the house to be heated, bearing in mind that it is better to have a reserve of heating power for extraordinary occasions. In such cases economy in fuel will be secured, as the fires will not be required to be kept constantly burning brightly.

Fault is sometimes found with the apparatus when it lies entirely with the proprietor of the establishment, who in his short-sighted economy, has restricted the builder in the amount of pipe put into the apparatus.

CONSTRUCTION, &c.

The general plan of Horticultural structures may be as perfect as possible, but if the details are not well carried out, and especially if the workmanship be not good, they will prove a source of never-ending vexation and expense. Insecure foundations, ill-fitting doors and ventilators, imperfect glazing, and inferior workmanship of every description, are evils that skillful gardeners have to contend with, and upon whom the consequences of such defects usually fall, when they should be placed upon the shoulders of the constructor.

Methods for building cheap Graperies and Green houses have often been described, and we find many of these imperfect and temporary structures scattered through the country. Such buildings may be cheap as respects their first cost, but their durability is a question which should enter into the calculations of their builders, as well as the consideration of the original outlay. After a year or two we find them with open joints, leaky roofs, and decaying foundations. The inferior and temporary character of materials and workmanship is often a source of serious loss to their owners, and every building of this description demonstrates the mistaken and short-sighted economy of its projector. It is much wiser and truer economy to expend at the outset, a sufficient amount of money and care to make the structure permanent, and to obviate the necessity of constant repairs. Experience has taught us that if they are well and substantially built, these structures will endure for twenty years with very few repairs except an occasional coat of paint. It need not be demonstrated that the profit and gratification to be derived from a well-built house far exceed those accruing from a cheap and imperfect one, with escapes for the heat in winter, and inlets for cold air and driving snow and rain.

The foundations of Horticultural buildings should be of stone or brick, both below and above the ground, if they are to be of a permanent character. The superstructure should be of the best white pine and thoroughly painted. In building curvilinear roofs the rafters and sash bars should be sawed out in pieces to the regular curve. The rafters being put together in sections, breaking joints are thus equally strong throughout their length. The advantages of sawed bars over those bent in the usual manner, are very great. The thrust of the roof is but slight, and the house always remains in shape. With the bent bars the strain is enormous, as may be seen in the settling of such houses at the ridge, and expansion at the sides, besides the liability of breaking the glass by the constantly varying strain of the bars.

Iron has been frequently and strongly recommended in the construction of horticultural buildings. It has been used, with very satisfactory results in England, and doubtless it may there be found to be the best and most economical material for such purposes. It has been tried also in this country, but the experiment has not resulted so favorably. The main difficulty is that, in this climate, the expansion and contraction of the iron rafters and bars are so great that the glass is continually and badly breaking, and it is very difficult to keep the joints tight enough to repel the rain and the cold air. There can be no doubt that in this country, wood is a better material than iron for these purposes.