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cannot be made without some detriment to such places. 
The natural flow of water is generally the best for cleansing 
and sweeping out a river or estuary, and such agency may be 
helped and diverted, but it can never be opposed or ob- 
structed with impunity. Owing to the want of reliable 
experiments it is not yet well known at what speed a 
current of water ceases to cut a bed of clay and begins to 
lift up the course of such water. All we know binadly is 
that mountain streams deepen and low country streams raise 
their beds. 
The estuary of the Mersey and its deep channels have 
been kept open chiefly by the ebb tide and the back waters 
of the Mersey, Weaver, and other streams. Of late years 
the shores on both sides of the Mersey have been extended 
into the water way by the construction of new docks and 
other works so that the channel is now considerably less in 
width than it formerly was, and consequently less water 
enters the river from the sea and flows up it than used to do, 
and thus diminishes the power of the ebb tide. True it is that 
the contraction of the river has made the current of the ebb 
for some time stronger opposite to Liverpool, and thereby 
increased the scour and cutting power there, but the 
materials removed soon fall to the bottom when the water 
course becomes wider and the current less, so this increased 
scour will not compensate for the loss of water caused by 
the obstructions to the flood tide but actually increase, to a 
considerable extent, the deposits of the removed materials 
in the vicinity of the bar. It is quite clear that the empty- 
ing of dock mud into the river is an evil, but what is it 
when compared to the solid matter brought down daily 
and in freshes by the inland streams feeding the Mersey. 
My object in making these remarks is to direct attention 
to the subject of the lowering of the depth of water over 
the Queen’s Bar, which is of the utmost importance to 
steamers leaving and arriving at the tidal harbours about 
