But there is a still more important fact to notice. The greenhouse has nowadays a tendency to become a mere kitchen garden under glass. And when it is used to such a purpose, the simplest plank-and-glass unheated shelters already give fabulous crops—such as, for instance, 500 bushels of potatoes per acre as a first crop, ready by the end of April; after which a second and a third crop are obtained in the extremely high temperature which prevails in the summer under glass.
I gave in my "Fields, Factories, and Workshops," most striking facts in this direction. Sufficient to say here, that at Jersey, 34 men, with one trained gardener only, cultivate 13 acres under glass, from which they obtain 143 tons of fruit and early vegetables, using for this extraordinary culture less than 1000 tons of coal.
And this is done now in Guernsey and Jersey on a very large scale, quite a number of steamers constantly plying between Guernsey and London, only to export the crops of the greenhouses.
Nowadays, in order to obtain that same crop of 500 bushels of potatoes, we must plough every year a surface of 4 acres, plant it, cultivate it, weed it, and so on; whereas with the glass, even if we shall have to give perhaps, to start with, half a day's work per square yard in order to build the greenhouse—we shall save afterwards at least one-half, and probably three-quarters of the formerly required yearly labour.
These are facts, results which every one can
