\Zi LITEBATUfeB ON TORHENta. 



Minister of the United States of America at Borne, — a work in which there 

 is embodied a great mass of valuable information on the subject of torrents, 

 or the extinction of these, and on subjedts closely related to these. 



I shall afterwards have occasion to quote at length statements by Mr 

 Marsh in regard to the provinces of Dauphiny and Provence, to the valley 

 of the Rhone, and to the department of D6voluy. His own remarks on 

 subjects connected with the occasion, phenomena, and control of torrents 

 are not less deserving of consideration. His position as Minister of the 

 United States at different courts, with a perception of the importance of 

 such matters, have given him exceptional advantages for the study of this 

 matter, as of much besides, of which he has conscientiously availed himself, 

 and embodied the results in his more comprehensive treatise. 



By the information supplied by such works as Les Inondations en France 

 depuis le Vie Siecle jusqu'd, nos jours, by Champion, and Les Forets de la 

 Gaule et d Vancient France, already cited, the student in this department of 

 forest science can carry back his studies to times that are past. 



Of these Mr Marsh writes : — " The remarkable historical notices of 

 inundations in France in the Middle Ages collected by Champion are con- 

 sidered by many as furnishing proof that, when that country was much 

 more generally covered with wood than it now is, destructive inundations 

 of the French rivers were not less frequent than they are in modem days. 

 But this evidence is subject to this among other objections : we know, it is 

 true, that the forests of certain departments of France were anciently much 

 more extensive than at the present day ; but we know also that in many 

 portions of that country the soil has been bared of its forests, and then, in 

 consequence of the depopulation of great provinces, left to reclothe itself 

 spontaneously with trees, many times during the historic period ; and our 

 acquaintance with the forest topography of ancient Gaul or of mediaeval 

 France is neither sufficiently extensive nor sufficiently minute to permit us 

 to say with certainty that the sources of this or that particular river were 

 more or less sheltered by wood at any given time, ancient or mediseval, 

 than at present. I say the sources of the rivers, because the floods of great 

 rivers are occasioned by heavy rains and snows which fall in the more 

 elevated regions around the primal springs, and not by precipitation in the 

 main valleys or on the plains bordering on the lower course. 



" The destructive effects of inundations, considered simply as a mechanical 

 power by which life is endangered, crops destroyed, and the artificial 

 constructions of man overthrown, are very terrible. Thus far, however, the 

 flood is a temporary and by no means irreparable evil, for if its ravages end 

 here, the prolific powers of nature and the industry of man soon restore 

 what had been lost, and the face of the earth no longer shows traces of the 

 deluge that had overwhelmed it. Inundations have even their compensa- 

 tions. The structures they destroy are replaced by better and more secure 

 erections, and if they sweep off a crop of corn, they not unfrequently leave 

 behind them, as they subside, a fertilizing deposit which enriches the 

 exhausted field for a succession of seasons. If, then, the too rapid flow of 

 the surface-waters occasioned no other evil than to produce, once in ten 

 years upon the average, an inundation which should destroy the harvest of 

 the low grounds along the rivers, the damage would be too inconsiderable, and 

 of too transitory a character, to warrant the inconveniences and the expense 

 involved in the measures which the most competent judges in many parts 

 of Europe believe the respective governments ought to take to obviate it. 



