[77] One could not insist too much on the collective character of the development of that branch of husbandry. In many places of the South coast of England early potatoes can also be grown--to say nothing of Cornwall and South Devon, where potatoes are obtained by separate labourers in small quantities as early as they are obtained in Jersey. But so long as this culture remains the work of isolated growers, its results must necessarily be inferior to those which the Jersey peasants obtain through their collective experience. For the technical details concerning potato-culture in Jersey, see a paper by a Jersey grower in the _Journal of Horticulture_, 22nd and 29th May, 1890. Considerable progress has been made lately in Cornwall, especially in the neighbourhood of Penzance, in the development of potato-growing and intensive market-gardening, and one may hope that the successes of these growers will incite others to imitate their example. [78] See Appendix L. [79] See the _Annales agronomiques_ for 1892 and 1893; also _Journal des Economistes_, février, 1893, p. 215. [80] Barral in _Journal d’Agriculture pratique_, 2 février, 1889; Boitel, _Herbages et Prairies naturelles_, Paris, 1887. [81] The increase of the crops due to irrigation is most instructive. In the most unproductive Sologne, irrigation has increased the hay crop from two tons per hectare (two and a half acres) to eight tons; in the Vendée, from four tons of bad hay to ten tons of excellent hay. In the Ain, M. Puris, having spent 19,000 francs for irrigating ninety-two and a half hectares (about £2 10s. per acre), obtained an increase of 207 tons of excellent hay. In the south of France, a net increase of over four bushels of wheat per acre is easily obtained by irrigation; while for market gardening the increase was found to attain £30 to £40 per acre. (See H. Sagnier, “Irrigation,” in Barral’s _Dictionnaire d’Agriculture_, vol. iii., p. 339.) I hardly need mention the striking results obtained lately by irrigation in Egypt and on the dry plateaus of the United States. [82] _Dictionnaire d’Agriculture_, same article. See also Appendix M. [83] Ronna, _Les Irrigations_, vol. iii., p. 67. Paris, 1890. [84] Prof. Ronna gives the following figures of crops per acre: Twenty-eight tons of potatoes, sixteen tons of mangolds, 105 tons of beet, 110 tons of carrots, nine to twenty tons of various cabbage, and so on.--Most remarkable results seem also to have been obtained by M. Goppart, by growing green fodder for ensilage. See his work, _Manuel de la Culture des Maïs et autres Fourrages verts_, Paris, 1877.