The Laying of a Sluice* 



To lay an iron cylindrical sluice well, the level of the 

 highest and lowest tide at spring-tide must first be accurately 

 marked; the bedding for it to rest in must be dug to two feet 

 below the level of the lowest tide. Here this level is 3-14 M. 

 or 10 feet. At neap-tide the flood is always 3 feet less high 

 than at spring-tide, and the ebb or fall is also never so low. 



At a depth of 36 inches below the surface of the ground 

 the earth dug out is worked backwards and on either side to 

 24 in. banks, until the requisite depth of bedding is obtained. 

 This manner of working must be observed that the weight of 

 the ground dug out do not cause a sinking and crumbling of 

 the sides of the embankment. 



The cylinder must be put together on the bank as close as 

 possible to the desired place ; the openings at either end must 

 be carefully closed water-tight. 



By means of trestles placed across the bedding the cylinder 

 is hoisted up with block and tackle to just over the 

 spot where it will have to lie, and is then gently let down into 

 it. On dry ground this operation is performed in the way 



