Tue very Latest Meruops. 397 
SECTION SECOND. 
AINSWORTH’S RACE AND SCREENS. 
‘i = 
= i wal 
wah 
SS ARTA UU fy Sas 
= 
A. Top of Race. B. Water Level. C. Upper Screen, or Sieve. D. Under Screen. E.- 
Bottom of Race. G. Supply Pond. H. Filtering Gate. 
The Upper Screen is represented from the ground-plan, in order to show the form of 
the perforated bottom, and the same after paving it with pebbles. The bottom of 
the Race is also represented from the same y ; but the side only of the Under 
Screen is represented. The whole is suggestive, calling for judgment and science 
in construction. 
The object of this invention is to induce trout to spawn where 
the fish-culturist may gather the eggs and protect them 
until he can transfer them to the hatching-boxes once or 
twice a week, and it is a valuable step on the road of agua- 
culture toward husbanding all the resources of a stream. 
The object is to form a race-way of water in a stream of 
moderate flow, and divide this race into three compart- 
ments. Those are the bottom of the race paved with cob- 
ble-stones, E; a few inches above it, and of the same width, 
is the lower screen or sieve, D; a few inches above which 
is the upper screen,C. Trout have access to screen C for 
spawning, and as the bottom of it is perforated with holes 
twice as large as a trout’s egg, of course the eges laid on 
it will run through the bottom of the screen and lodge on 
the under one, which is perforated with very small holes 
to drain it, but not pass the eggs. Sereen C is divided into 
trays, with handles at the sides for removing them by the 
hand; the bottom is then covered with pebbles, as indi- 
