REARING 209 



prevent the inlet from becoming clogged by leaves, 

 weeds, and other floating matter collected and drawn 

 against it. The outlet of a yearling pond should be 

 so placed as to ensure free circulation for the current 

 through the entire length and breadth of the pond. 



Two-year-olds require less current, but their ponds 

 should be wider and deeper, although not necessarily 

 longer than the yearling ponds. It must not, however, 

 be forgotten that a wider pond exposes a larger surface 

 to the sun's rays, and if there is danger of over-heating, 

 shade must be provided. 



A convenient arrangement for a series of ponds is 

 where they are separated by perpendicular dams or 

 sluices formed by water-boards which slide into the 

 grooves of a frame firmly fixed in a heading of brick- 

 work, as shown in the illustration (fig. 16). By means 

 of these boards the height of water in each pond can 

 be easily regulated. 



To the topmost board of each sluice is attached a 

 shoot of charred wood. To head up the water and 

 increase the capacity of a pond you simply pull out 

 the top board of the outlet sluice, and before replacing 

 it insert an additional water-board of the required width. 



The outfall of each pond forms, as will be seen, a 

 waterfall at the inlet of the pond immediately below 

 it. The greater the fall from one pond to the other 



p 



