328 OONOIiUSION. 



CONCLUSION. 



It has been my desire and my endeavour, in preparing the statements 

 contained in the preceding pages, to supply such information as might enable 

 any student of hydraulic engineering or of forest science to form an intelligent 

 idea of what has been done in France in carrying out works of rehoisement 

 and gazonnement, with a view to arresting and preventing the destructive 

 consequences and effects of torrents, and of the consequences and results 

 which have followed, and, in conclusion, I submit for the consideration of 

 any who may inhabit lands exposed to ravages of torrential floods, whether 

 like measures in like circumstances be likely to produce like effects. It 

 might be as imprudent to apply to some one case exactly the same measures 

 which have proved successful in some one or other of the cases which have been 

 brought under consideration as it would be for a nurse to follow in every 

 case in which her services might be required precisely the same course of 

 treatment which she saw followed with success in some one case for 

 which prescriptions and directions were given by a physician of renown. 

 Better do so, perhaps, than disregard altogether what she may then have 

 seen ; but it holds good in medicine as well as in law that the case being 

 altered that alters the case, and it holds good in the treatment of torrential 

 floods by rehoisement, as well as in medicine, that each particular case de- 

 mands particular consideration and a particular application of the general 

 principles to be followed in its treatment. We have found it laid down in 

 the treatises which we have laid under contribution that not only each 

 torrent but each affluent requires to be specially studied and to be specially 

 treated. 



To distinguish things which difier is as necessary as to perceive the 

 analogies in which things agree. A rash generalisation, extending the 

 process of induction — or what seems to be such — ^beyond the facts ascer- 

 tained, is to be deprecated ; but it is otherwise with deduction from what 

 is actually ascertained, and I speak advisedly when I say, that a prompt 

 and judicious application of measures which may be suggested by what has 

 been accomplished by rehoisement and gazonnement, in combination with 

 barrages, in France, might prevent much destruction of property and of life. 



While the preceding pages have been passing through the press there 

 has occurred in France one of those periodical inundations which it is 

 sought to prevent, and which present a form of the evil with which the 

 inhabitants of newly-settled lands — for whom more especially I write — are 

 more familiar than they are with the form of the evil for which rehoisement 

 and gazonnement were previously employed as remedial measures ; and it 

 may be that to some of them, as to others, it may appear that this is an 

 indication that the measures have failed to produce the efiect that was 

 anticipated, and for which they have been employed ; and I feel as if my 

 work would be incomplete if I passed over this view of the case in silence. 



There have been many inundations in France — as there have been else- 



