DECOYS AND THEIR WORKING 117 



sustain net, forming a tunnel known as a pipe. The 

 number of pipes may be from one to a dozen or so, 

 according to the size of the water. The Wretham 

 decoy in Norfolk has ten pipes, a larger number than 

 that possessed by any other active decoy in the 

 Eastern Counties, if not in our islands. Iron sup- 

 ports, their ends firmly embedded in the soil on 

 either side of the channel, are used at the mouth of 

 the pipe and for some distance down, and saplings 

 as the channel narrows. The supports are placed 

 at intervals of about five feet. These arches are 

 usually about twelve feet high and twenty feet 

 wide at the mouth of the pipe. They become 

 smaller and smaller, till at the end of the pipe 

 they are found to be only two feet high : thus 

 when the whole structure is covered with net we 

 have a gradually narrowing and curving pipe, the 

 course of which cannot be seen by the duck till their 

 retreat is cut off. At the end of the pipe is a detach- 

 able bag-shaped net, known as a tunnel-net. The 

 length of a pipe is usually about seventy yards. On 

 the bank of the decoy, and for some way down the 

 convex side of a pipe, are screens, six feet high, and 

 covered with rushes, so arranged in echelon that the 

 decoy-man can pursue his tactics without being seen 

 by the birds on the water, and yet can show himself, 



