Woodward's Graperies and Horticultural Buildings

by George E. Woodward; F. W. Woodward

1. A larger run of roof for a given width of house, and consequently, more and better diffusion of light.

2. A greater power of reflecting the sun's rays, because of the constantly varying angle at which they strike the glass.

3. A greater amount of head room within the building, without the necessity of high parapet walls, or perpendicular sides.

4. Greater strength of the roof, enabling it to resist pressure from accumulated snows, without the necessity of supporting columns under the rafters, which are indispensible under a straight roof of considerable span, to prevent its settling down, and the opening of joints in glass and wood work, admitting the cold air from without.

A good proportion for a grapery or conservatory, is twenty feet in width by fifty feet in length. We think the width should never be much less where the roof is of double pitch. Single pitched houses should not exceed sixteen feet in width.

Mistakes are frequently made in the erection of structures for the growth of plants which, notwithstanding all the skill and art of experienced gardeners, render it impossible to arrive at satisfactory results. One of the most common of these is the excessive height of the roof. Men of experience in the construction and use of glass houses, have satisfied themselves that the lowest elevation which the uses and purposes of the building will admit, is the best. The difference in temperature between the floor and roof of a house twenty feet in height, will vary from ten to fifteen degrees. It is obviously desirable that there should be as little difference as possible in the temperature of the air on the ground, among the lower parts of the plants, and in the upper regions of the house. The nearer we can approach an equilibrium, the better success will attend our efforts. Nurserymen generally, and sometimes other cultivators, understand this, and they build their plant houses with roofs of low pitch, affording scarcely room to stand upright within them. Their plants are thus brought near the glass, and they grow stocky and firm, presenting quite a different appearance from the attenuated specimens frequently met with in private establishments.

HEATING.

The proper heating of Horticultural buildings being an important feature in their general management, and an essential condition of their success, we shall consider the subject at some length, availing ourselves of the practical experience of others, as well as of the knowledge we have acquired in our own experiments and practice.

Hot air stoves have been so generally condemned and discarded as a means of heating glass structures, that we shall not discuss their faults or merits, but confine ourselves to heating by flues, steam, and hot water in pipes and tanks.

Flues.—Flues have been generally used in heating for many years, and although the method is rude, imperfect and unsatisfactory, they possess certain advantages on the score of economy, which will prevent their total supercedure until some equally cheap and effective method shall be found, to take their place. It cannot be questioned that houses of moderate extent can be heated at much less expense for the original cost of apparatus by the flue system than by any other now before the public. Flues have the advantage over steam or hot water in their power to generate heat and supply it to the green or hot house in a very short space of time, and with this apparatus, the fires may be allowed to go out on mild and bright days in winter, with the certainty that heat can be easily and quickly commanded at nightfall. Steam cannot be generated quickly, and the hot water apparatus requires considerable time to get into full operation, with the usual amount of fuel.