FOE PLEASURE AND PROFIT. 33 



Let us suppose that pcmd A is to be emptied, atidi that ponds B 

 and c remain full (or nearly so) with water running into and 

 out of them continually while operations axe going forward in 

 pond A. Sluice H is adjusted so that no water can enter from 

 the surplus water channel K K K. Sluice L is adjusted so that 

 the water has free access down the channel K K K. Sluice M 

 is adjusted so that a sufficiency of water is diverted into the 

 branch channel N, and so into the pond c, by way of sluice J. 

 Lower the height of water in pond B by means of the sluice 

 E E four inches, or even six, so that no water flows through 

 the screen G. Now empty your pond A at the sluice E. While 

 the operations in pond A are going forward, the water is 

 flowing from the channel K K K into the pond c over the 

 sluice J. Should there be a shortage of water in the channel 

 K K K, it is remedied in the following manner: Pond B has 

 a similar branch channel to o, in connection with A, and N, in 

 connection with c, and ai similar sluice to those at 

 H and at J. Adjust this sluice so that the top board is 

 slightly lower than the top board at sluice E E; the surplus 

 water, instead of flowing down the controlling sluice E E, falls 

 over the sluice at the branch channel, and so joins, and adds 

 to, the volume of water flowing down the channel K K K. But 

 if your levels are right and your sluices in the channel properly 

 adjusted, this shortage of water will not occur. 



Several little matters that may, perhaps, puzzle you now 

 will be made quite clear in the chapter on " Sluices." It may 

 be thought that the method of handling the ponds is compli- 

 cated and expensive, but when you learn how simply and 

 cheaply the apparatus is made and fixed any such idea will 

 be abandoned at once. 



The next photographs illustrate the method of forming 

 ponds in a hilly district ; the sheets of waiter, indeed, are of 

 such proud proportions that they acre entitled to the term of 

 lakes, especially the lower one, of which I managed to get a 

 decent view. The problem in this case was quite a common 

 one. In a very hilly district, amid grouse moors and rabbit 

 warrens, a stream tumbled noisily down a rocky gorge be- 



D 



