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long, ten inches wide, and two inches thick, were then laid npon this 

 bottom at intervals of about three feet from centre to centre upon a 

 a circle of fifty-four feet in diameter, and the whole carefully levelled. 

 A band of wrought iron fifty-four feet in diameter, half an inch thick, 

 and twenty-two inches wide, was then obtained and placed upon this 

 ring of plank. The band was made of sheets about fourteen feet long, 

 the ends of which were placed together, forming butt-joints ; over these 

 ran covering plates, three feet long, and double counter sunk rivets 

 were used to secure them. These having been put in place and 

 brought to a true circle, a ring of oak timber, eleven inches thick, 

 .eleven inches wide on the top and two inches wide at the bottom, was 

 placed inside of the iron band, the thin edge resting on the short plank, 

 and being in contact with the iron. This was securely fastened to the 

 band by means of bolts and spikes, Upon this was laid another ring 

 of oak timber six inches thick and twenty-four inches wide, the inner 

 diameter of the ring being fifty feet. These two rings were 

 securely fastened together by spikes ten inches long and half 

 an inch square. Seven courses of oak of the same dimensions as 

 the last were then laid up, making a total depth of timber of four feet, 

 the whole securely spiked and bolted. The iron band reached to the 

 top of the second six-inch course of timber, and the third course pro- 

 jected over its edge so as to come flush with the outside of the iron, 

 thus forming a shoulder against which the iron could press, and which 

 would prevent its being forced upon the outside of the curb. Fortv 

 holes were then bored through this four feet of timber, to receive the 

 rods of one and one-half inch round iron which were sixteen feet 

 long. These rods were passed through this mass of timber and were 

 held in position at the top by a turnplate. The wall of brick masonry, 

 two feet thick, was then commenced upon this wooden curb, and 

 carried up to a height of ten feet, where four layers of pine timber, 

 each six inches thick and sixteen inches wide, were introduced. These 

 were placed in the centre of the wall, and the iron rods passing 

 through them were securely bolted down with heavy washers and 

 nuts. The wall was now sixteen feet high, besides the cutting edge, 

 which projected ten inches below the main wall, and was securely 

 bolted together. "While this was being done a suitable Derrick had 

 been obtained, and so placed that the boom would swing over the wall 

 and command the interior space also. Iron buckets for hoisting out 

 the sand, and a six-horse-power hoisting engine were procured. "Work 

 was then commenced upon the excavation. The material from within 

 the wall was excavated and thrown into the iron buckets, and was 

 then hoisted out and taken awav. The excavation in the centre was 



