ATKINS ON FISH-WAYS. 603 



sometimes lie there in perplexity, until, wearied by exertion, drunk and 

 ^iddy frofu the continual wliirling, they abandon the attempt and fall 

 back out of the fish-way. That the fish will sometimes be so perplexed 

 as to back out of the fish-way is sufficiently plausible to warrant the 

 avoidance of the causes that lead to it, even at considerable cost. It is 

 also quite likely that fishes, like other creatures, are capable of being 

 made dizzy by continual whirling ; but I can hardly think it possible 

 that this ever occurs in the pools of any well-proportioned fish-way of 

 any of the styles that have been in vogue in the United States during 

 the last ten years. Nor does it appear likely that the expenditure of 

 strength in stemming eddies is ever sufficient to be of great moment. 

 The loss of time, however, is a serious matter. While in a fish-way, as 

 well as below any barrier, fish are liable to be turned back by fright, 

 or, in the case of alewives, by the approach of night, and delayed per- 

 haps for many days in their journey, and exposed so much longer to the 

 various mischances that beset them. The quicker, therefore, they can 

 be got through the fish-way and past the obstruction the better. 



It was formerly supposed that flsbes required frequent opportunities 

 for rest, and no plan was thought complete which did not include a 

 n amber of i)ools for that purpose. The general tendency of the results 

 of more recent study is to the conclusion that no such resting places are 

 necessary ; tlie fishes being capable of long-continued exertion, and 

 accomplishing the ascent with much greater speed and certainty when 

 kept close at their task than when allowed to idle along in pools and 

 eddies. 



Thus it appears that eddies are of no value as resting-places, because 

 they are not needed, and that they are probably, to a certain extent, 

 positively injurious by delaying the advance of the fish. They may 

 theretore be dispensed with, not only without detriment but probably 

 with advantage. Taking this view of the case, our aim will be to pro- 

 duce a simple and uniform flow of water. Perfection in these respects 

 is neither practicable, nor, as many instances prove, necessary. There 

 are not wanting instances of fish ways with large and strong eddies that 

 worked admirably; and even in the best elaborated fish- way that has yet 

 been introduced, the eddying and swirling of the water is not entirely 

 obviated. 



D— DEVICES WHICH ARE IN" USE OR HAVE BEEX PRO- 

 POSED. 



Fish-ways may be classified with reference either to their details or their 

 general arrangement. 



With reference to details they may be grouped thus: 

 Gap. 



Trench, ditch, or "Cape Cod'' fish-way. 

 Oblique groove: 



1. Single groove. 



2. Brewer's. 



