of acres are already covered with glass—to say nothing of the countless small greenhouses kept in every little farm garden. Acres and acres of greenhouses have lately been built also at Worthing, in the suburbs of London, and in several other parts of England and Scotland.
They are built of all qualities, beginning with those which have granite walls, down to those which represent mere shelters made in planks and glass frames, which cost, even now, with all the tribute paid to capitalists and middlemen, less than 3s. 6d. per square yard under glass. Most of them are heated for at least three or four months every year ; but even the cool greenhouses, which are not heated at all, give excellent results—of course, not for growing grapes and tropical plants, but for potatoes, carrots, peas, tomatoes, and so on.
In this way man emancipates himself from climate, and at the same time he avoids also the heavy work with the hot-beds, and he saves both in buying much less manure and in work. Three men to the acre, each of them working less than sixty hours a week, grow on very small spaces what formerly required acres and acres of land.
The result of all these recent conquests of culture is, that if one half only of the adults of a city gave each about fifty half-days for the culture of the finest fruit and vegetables out of season, they would have all the year round an unlimited supply of that sort of fruit and vegetables for the whole population.
