Plate XXI. 



Fig. 1. Tlie Sw.izey Plrxn, invented by Alfred Swazey 

 of BiieksjKjrt, Sraine. 

 2. Tlie siime, with additions, by C. G. Atkins. 

 a. The Foster Plan. 



Fig.4. Same, modified; as built ou Penmaquan Kiver. 



5. From a design for a fishwaj" on Androscoggin 

 Kiver. Aug. 1870. 



6. Tlie Brackc'tt plan, patented by E. A. Brackett uf 

 Massacliusetta. 



