03 A STATISTICAL ACCOUNT, Of* THE 



" On the 5th September the first stone of the pier was laid. 

 This day we fortunately kept the water out all day ; the ma- 

 sons xvorked 13 hours without refreshment ; except a little 

 drink. We were now unanimously of opinion, that our diffi- 

 culties could be overcome ; nevertheless, we were obliged 

 to work night as well as day, when the tide answered," [the 

 leakages always increased, owing to the greater head of wa- 

 ter at high tide] " until we got above low water mark. We 

 were then at ease ; but little pumping afterwards. The wa- 

 ter shoots^^ laid in the dam, served to regulate the tide after- 

 wards on all occasions, until the masonry was finished." 



* Water shoots were tubes, in the first, and truiiks in the second dam, fur- 

 nished with valves, or shutters, so as to permit the exit of water, but t® 

 repel its entrance, and to be opened, or entirely closed at pleasure.— 

 They were placed just above low water mark ; and while the dam was- 

 filling- with puddle, suffered to remain open for the flux and reflux of the 

 tide ; or shut when circumstances required. The dam could of course 

 be always emptied to low water mark, without pumping- ; and by clos- 

 ing the shoots, the tide was entirely excluded. But a great length of 

 time elapsed, while the puddle was filling, and consolidating, before it was 

 safe entirely to exclude the tide. The water, inside the dam, was a 

 great counter balance ; not only to the pressm*e without, but to that of 

 the settling puddle. None but those who have experienced it, can con- 

 ceive the almost resistless force of earth, while consolidating : and the 

 puddle of these dams consisted of several thousand cart loads. The ad- 

 mitting and excluding the water, required great care and judgment ; and 

 frequent trials were made, before the risque was encountered of the entire 

 exclusion of the tide. Before the earth of the puddle was sufficiently em- 

 bodied, to sustain itself, the work had to support not only its weight, but 

 tlie immense force and irregular protrusions and pressures, of parts differ- 

 ently composed, and settling faster or slower than others. 



Every kind of earth, or substance, any wise proper, was tried for Jllling 

 or puddle. 



Crude brick ov potter'* s clay, settled unequally, and cracked when other- 

 wise consolidated. Tempered clay was little better. 



Miver mud was bad ; it had some of the properties of clay. 



Gravel, was good for the filling- of the abutments ; but not proper fc?l' 

 *he dam. 3o was it with sand. 



