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,
