58 How to obtain tt. 
one third the size of hazel nuts, and one third the size of peas. 
The two first may be mixed together and laid at the bottom, the 
smaller stones forming an upper layer. Over this may be 
scattered, so as to form just a covering, a very thin layer of 
material, which may be described as fine gravel or very coarse 
sand. Care must be taken, however, to keep out of the raceway 
anything of the nature of fine sand. 
In width this raceway should be about three feet, and should 
the natural gradient be too steep, a fall, or perhaps more than 
one, should be made, so as to bring the part available for 
spawning to a proper level. ‘The best place for this fall is at the 
leaf screen, if it can be so arranged, or at the point where the 
water enters the pond. By making it at either of these places the 
spawning race is not so much interfered with, but, of course, 
much must depend upon the nature of the ground. This being 
done the gravel should be put in. Then a series of very low 
weirs should be made. ‘They need not stand more than six 
inches above the water level, but the depth of the water itself 
in the reaches formed by these obstructions should run from six 
inches to a foot. Whilst the raceway is being prepared the water 
should be shut off so that the work may be properly carried out. 
The reaches of water may be ten feet or ten yards in length, 
according to circumstances. The divisions between each are 
best made of stones or blocks of concrete. JI have seen very 
effective ones made by simply placing logs across the stream, and 
where plenty are at hand and stones are scarce they do very well. 
Having formed these miniature dams and made all right, the next 
thing is to turn on the water and wait results. The effect of the 
current will be to wash out holes below the weirs, and probably 
to form a bank just beyond each of these holes. One great 
advantage of having the water under control is now apparent, and 
that is that the bottom of the raceway can be raked over, and the 
gravel spread to suit circumstances. These banks may be raked 
down, and the gravelly bottom otherwise improved, if found 
desirable, by hollowing it out a little in the middle. When the 
fish come up they will soon make short work of it, however, 
rooting it up everywhere in making their nests. 
At the spawning time especially, as well as at other times, it 
