THE FISHERIES. 43 



ture to say that if opened at the occurrence of the 

 first flood in October, the mill-owner will not have 

 occasion to close it until March or April following, 

 as the river (except some very petty stream) will 

 hold its winter level during the whole of that period 

 — in other words, the run of water in the river will 

 maintain its level and flow over the top of the weir, 

 although the aperture be open; should the contrary, 

 however, at any time occur, the miller has the re- 

 medy in his own hands ; he closes the opening as he 

 would close any waste-gate of his mill ; but, as de- 

 monstrative of the general efficiency of a pass con- 

 structed in this manner, we can state that we have 

 seen in many rivers flood-gates discharging, at least, 

 ten times a greater volume of water (seven feet by 

 five) remain open with the miller's assent, and by 

 the miller's own act, for six months together, until 

 the very cogs of the winch became rusty — but, as 

 already stated, the material fact will remain at all 

 times undisplaced ; the miller can close the aperture, 

 if he becomes inconvenienced, and the pass will be 

 effective and available under the existing enactments, 

 once in each week throughout the year. 



Our next device, we hope, will complete the series, 

 as the subject here discussed, though important, is 

 necessarily tedious. Amongst various plans and 

 specifications which we have seen (many of them 

 quite absurd, inasmuch as they assume that a salmon 

 can ascend a weir without water) it has never been 

 proposed, that we are aware of, to construct a migra- 



