SCOURING AND SLUICING. 



287 



wings and within the line of current against the river 

 wall. 



The bursting of the temporary dam after the completion of 

 the excavations within it down to the full depth of 21 feet 

 below the old dock sill caused a deposit of 10 inches on the 



v, 1 i 



^-r:::^HP-^ 



floor, which was increased to 32 inches by the daily tidal 

 influences, within a period of seven months. 



The following extracts and particulars of the trials which 



took place to prove the efficiency of the arrangements, and the 



results which ultimately led to the abandonment of the work as a 



low- water basin, are taken verbatim from the Institution's papers. 1 



1 M.P.I.C.E., vol. xxviii. p. 526. 



