And yet the market-gardeners of Paris and Rouen labour three times as hard to obtain the same results as their fellow-workers in Guernsey or in England. Applying industry to agriculture, these last make their climate in addition to their soil, by means of the greenhouse.
Fifty years ago the greenhouse was the luxury of the rich. It was kept to grow exotic plants for pleasure. But nowadays its use begins to be generalized. A tremendous industry has grown up lately in Guernsey and Jersey, where hundreds 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 (103 acres in 1912), 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 of 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 hotbeds, 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, produce 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.
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, thirty-four men, with one trained gardener only, cultivate thirteen acres under glass, from which they obtain 143 tons of fruit and early vegetables, using for this extraordinary culture less than 1,000 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 four 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 yearly labour required formerly.
These are facts, results which everyone can verify himself. And these facts are already a hint as to what man could obtain from the earth if he treated it with intelligence.
V
In all the above we have reasoned upon what already withstood the test of experience. Intensive culture of the fields, irrigated meadows, the hothouse, and finally the kitchen garden under glass are realities. Moreover, the tendency is to extend and to generalize these methods of culture, because they allow of obtaining more produce with less work and with more certainty.
In fact, after having studied the most simple glass shelters of Guernsey, we affirm that, taking all in all, far less work is expended for obtaining potatoes under glass in April, than in growing them in the open air, which requires digging a space four times as large, watering it, weeding it, etc. Work is likewise economized in employing a perfected tool or machine, even when an initial expense had to be incurred to buy the tool.
Complete figures concerning the culture of common vegetables under glass are still wanting. This culture is of recent origin, and is only carried out on small areas. But we have already figures concerning the fifty years old culture of early season grapes, and these figures are conclusive.
In the north of England, on the Scotch frontier, where coal only costs 3s. a ton at the pit’s mouth, they have long since taken to growing hothouse grapes. Thirty years ago these grapes, ripe in