Page:The Amateur's Greenhouse and Conservatory.djvu/18

12 of the former as to protective power and duration, but in favour of the latter as to lowness of first cost. As to rafters, those of wood are more perishable than iron, and admit less light. On the other hand, wood is a non-conducting substance, and if a nice comparison were made it would be found that a house with a light iron roof would cost rather more for fuel than a house of the same shape and dimensions with wood rafters, to maintain an equal temperature throughout the winter. But light is life, and iron roofs are adapted to catch the utmost glimmer of the weak daylight of this cloudy clime, and in the case of a structure intended for succulent plants, and such other subjects as need the fullest possible flood of light, iron is certainly to be preferred. In the case of a large conservatory iron is unquestionably superior to wood, and the more so with every advance in elegance of construction.