84 PATENT ROLLER SPAWNING BOX. 



in a careful manner and return each screen to its proper 

 place. 



It would take the new spawning box about fifteen min- 

 utes to do the same work, with one man. 



2d. The weight of the gravel which has to be lifted 

 in the old way, amounts to many tons in the course of the 

 season. 



In the new box, the gravel is not lifted at all. 



3d. By the old way the operator's hands must, of neces- 

 sity be more or less wet during the whole operation. Now, 

 as the Trout, &c., spawn during the winter season, it may 

 be imagined how pleasant this feels when the thermometer 

 is anywhere below the freezing point. 



By the new way the hands are not made wet, and may 

 be kept comfortably gloved. 



4th. By the old way, more or less of the eggs are lost 

 by careless feathering, exposing the eggs to the freezing 

 atmosphere, clumsiness in handling the screens by cold 

 fingers, &c., &c. 



By the new way, every egg is saved. 



5th. By the old method every fish is driven out of the 

 race when the eggs are taken. Some of them will not re- 

 turn, but will seek a spawning place in the pond," and many 

 eggs will be unavoidably lost. 



By the new way the fish are not driven from the race. 

 And, as the boxes are always covered during the season, 

 the fish will not even be disturbed. In fact they may 

 spawn while the eggs are being taken, and yet not a single 

 egg be lost. 



This spawning box answers for securing the naturally 

 impregnated eggs of Salmon, Salmon Trout, Speckled 

 Brook-Trout, Whitefish, Shad, &c., &c. 



The screens, F and D, are so made that while a full cur- 

 rent is permitted to flow over the upper screens, (A), only a 



