The v.liole of the dyking to be made by two parallel walls of four feet thick, each at the distance of seven feet, from the inside of one to the inside of the other : The solid contents of the masonry is computed at 150,000 cubic feet : A mason will My of such work 60 cubic feet per day 1125

One man to attend tlie mason 2500 days at 4s 500

Carting the stones, at Is for every 20 cubic feet, for 150,000 cubic feet 375

The spaces between tlie walls of the dykes to be tilled with eartlior stone ; the latter preferable, when cemented with quick lime : Tlie solid contents to be filled about 80,000 cubic feet at Is. for carthig tlie stone is. . 200

5000 Bushels of lime at Is 250

Five locks besides the guard lock will be required : If these extend each 70 feet, and the projections beyond each 50 feet more the whole extent will be 720 feet But as all tlie work must be double on each side, the whole length will be 2880 feet : If tlie timber be 12 inches squares, and the sides 10 feet high, it will require 28,800 cubic feet. For bottom sills, one to every 3 feet, is 180 of 30 feet long, equal to 5400 cubic feet.-- 360 posts, 10 feet long, is 3600 cubic feet. Braces to cross Irom the interior to the exterior side -- one for

INLAND LOCK-NAVIGATION. 1105