614 EEPOKT OF COMMISSIONER OF FISH AND FISHERIES. 



the fisli-way completely, as iu the rectangular style, with a passage-way 

 at the upper end of each partition, on alternate sides of the fish-way. 

 This was at first thought to be an important improvement, but is now 

 regarded with less favor. Its action does not differ greatly from that of 

 the comraou rectangular fish-way, while the obliquity of the partitions 

 interferes with the introduction of arms like those in Brackett's and 

 some other styles, and with its adaptation to the reversed and spiral 

 arrangements. A good many of these have been built iu Maine, and 

 quite a number are now in successful operation. 



A better device than Foster's is one recently. invented (Plate XXI, fig. 

 1, plan ; fig. 2, same, with additions, by C. G. Atkins) by Mr. Alfred 

 Swazey, of Bucksport, Me., in which the passage-ways are all near the 

 center of the fish-way, but discharge the water iuto two series of pockets 

 arranged on each side. The movement of the water in a model four 

 feet wide is admirable. 



11. — GE^'EEAL ARRAMGE7.IENT. 



Of the three modes of general arrangement mentioned above, namely, 

 the extended^ ihQ reversed^ and the fqjiraJ^ the first being the simplest, has 

 been most generally adopted. The disadvantages attending it have 

 been considered sufficiently under the head of location. Though on low 

 dams and iu exceptional cases it proves quite satisfactory, it is utterly 

 unfitted for the majority of cases; and to its use in locations where it 

 carries the mouth of the fish-way to a great distance from the dam, I 

 attribute a large share of the failures that have occurred. 



The reversed form is far superior to the extended when applicable, as 

 it generally is. Considering only the question of its adaptation to the 

 requiremeuts of the fish, it is fully equal to the spiral. But when the 

 questions of economy of space and material are brought into consider- 

 ation, it is found that the reversed form has no advantage over the 

 extended, and that both these are far inferior in these respects to the 

 spiral, which is the ne phis ultra of fish-ways. 



The spiral form may be given to almost any of the step and inclined- 

 plane fish- ways, but to some with greater facility than others. The easi- 

 est to adapt are the rectangular plans, such as Smith's, Gail's, Brackett's, 

 and the common rectangular. So far as I know, only three styles of 

 spirals have thus far been devised, namely, Pike's, Gail's, and an adapta- 

 tion of the rectangular-compartment fish-way. Pike's is originally and 

 essentiallj- of this form. It is described above among the step-fish-ways? 

 and illustrated in plan and perspective, (Plate XXIX, figs, land 2.) Gail's 

 spiral* is an adaptation of his step-fish- way described above. Each circuit 

 consists of 4 pools, arranged in a large square ; the descent from pool to 

 pool being IS inches, a descent of G feet is accomplished in a single circuit. 

 The dimensions proposed by Mr. Gail (for small rivers, I suppose) are 

 as follows : pools, G feet square and 3 feet deep ; inlet, 11 inches square ; 



* See illnstratiou. 



