On reclaming Marsh Land, 63 



while the two outer spaces are to be considered as sup- 

 ports or footings to the whole ; so that by packing the 

 hardest mud in these outer spaces against the pilings of 

 the inner rows, it is apparent that the whole pressure of 

 the weight of mud will be directly downward ; nor can 

 the body of mud incline either to the right or left of these 

 middle raws of pilings, because a like quantity of mud 

 being thrown into each of the outside spaces, will pro- 

 duce a like pressure upon the centre of the dam. For 

 these pilings I would prefer two-inch plank, sawed to 

 suit the varying depths of the water, because they are 

 more easily pointed and more quickly driven to their pro- 

 per places by three men using a plank, as prescribed in 

 laying down the sluice. In filling up these spaces, (par- 

 ticularly the middle one) it will be necessary to observe 

 that no more work is to be laid off for the day than can 

 be secured and completed, so that it may not be swept 

 away by the current at night. In doing this, no greater 

 distance along these four rows of ties should be piled, 

 than can be filled up by the hands during the day ; and as 

 preparatory to filling up the day's w ork, three light ties 

 or sticks of timber, about six inches in diameter, and of 

 length suiHcient to reach across each of the three spaces, 

 should be laid across the long ties and rested for support 

 against the posts. Within and against these moveable 

 ties, good plank should be stuck down close to each 

 other, and as mucii mud should be thrown within, as 

 would support them firmly to their places, and enable 

 them to resist the impetuosity of the tide. Without 

 these precautions the rapidity of the current would carry 

 away the mud as fast as it was thrown in. This process, 

 called cribbing, is necessary to be repeated at every lay- 

 off of the work. From these cribbings, in the middle 

 space, the mud is to be sloped backward, towards the top 

 of the bank that had been previously finished ; and be- 



