THE TIDAL REGIME OF THE MERSEY. 319 
along the tidal portion of that river, the Committee considered that 
they would be in possession of the most accurate and authentic records 
respecting the tidal action which has been, and is at present, taking 
place in the Mersey. The Committee therefore instructed the Secre- 
tary to communicate with the Mersey Docks and Harbour Board to 
ascertain what information they would be prepared to afford to the 
Committee. 
It may not be out of place here to refer to the causes which have 
led to the appointment of this Committee. During the past thirty 
years several communications, and reports of Committees, connected 
with tides in the River Mersey have been presented to the Associa- 
tion. In 1885 Professor George Darwin communicated to the Royal 
Society a paper, summarising the results of the Harmonic Analysis of 
the Tides at various points—amongst others Liverpool—between 1857 
and 1870. 
It is well known that of recent years, commencing in 1890, great 
improvements, by dredging, have been gradually carried out in the entrance 
to the Mersey and in the approach-channels to Liverpool. In this way 
about eighty million tons of sand have been removed, and about 16 feet 
of additional depth over the bar, at the seaward entrance, have been 
secured for the navigation. The gradual extension of the dock and other 
river walls of late years have also provided for the tidal flow, a smoother 
and more regular channel in the Mersey. 
It was therefore thought possible that the form of the tidal wave might 
have been somewhat affected by these causes, and that it might be ad- 
visable, in the interests of science, to verify again by means of the most 
recent tidal records the results previously arrived at, by the Harmonic 
Analysis of the Liverpool tides of some forty years ago. Hence the 
appointment of the present Committee. 
The Mersey Docks and Harbour Board, when approached by the 
Secretary of this Committee, intimated through their General Manager, 
Mr. Miles K. Burton, that it would afford them much pleasure to assist 
the Committee in any way they could ; and they directed their Marine 
Surveyor, Commander Henry Belam, R.N., to afford the Committee access 
to any documents which might be deemed desirable, in order to further 
the objects of the Committee. 
After some further correspondence it was decided that ‘The Register 
of Tides at the George’s Pier, Liverpool, for the year 1902’ would 
be best suited for Harmonic Analysis; and these records were ac- 
cordingly handed by the Marine Surveyor to the Secretary for that 
purpose. 
Mr. Edward Roberts, of the ‘ Nautical Almanac’ Office, well known 
in connection with Tidal Harmonic Analysis, who had carried out the 
calculations of the previous investigations into the Liverpool tides of 
1857 to 1860 and 1866 to 1870, was good enough to offer the Committee 
to investigate the tidal registers of 1902, free of expense to them, so far 
as was necessary to ascertain whether there was any material difference 
between the results for the later period, and those of the two earlier 
ones. 
This offer of Mr. Edward Roberts having been accepted by the Com- 
mittee, with thanks, the ‘Register of Tides at the George’s Pier, 
Liverpool, for 1902,’ above referred to, was handed to him. Although it 
was only towards the end of May that it was found possible to do so, yet 
