The Conquest of Bread by Peter Kropotkin

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.