Observations on the Temperature of the Mersey. 307 



periodical or other works as are likely to obtain immediate 

 and extensive circulation. 



James D. Dana. A. Binnbt. 



S. S. Haldeman. C. U. Shepakd. 



p. H. Storer. C. Dewey. 



A. A. Gould. J. D. Whelplet. 



E. C. Herrick. 



Observations on the extent and rate of Change of Temperature 

 of the Waters in the Estuary of the Mersey at Liverpool. 

 By Mr Ritchie Adie. Communicated by the Author.* 



The present communication has for its object to shew that 

 the extensive sand-banks connected with the estuary of the 

 Mersey, exercise much influence on the temperature of the 

 tidal waters, which pass and repass twice every day through 

 a valley of sandstone-rock contiguous to the dock- wall of this 

 port. The velocity of the current in this valley varying from 

 2 to 6 miles per hour, with a mean hourly rate of 4 miles 

 per hour, has the effect of thoroughly mixing together the 

 water, so as to afford a favourable place for obtaining uni- 

 form results. 



The bay of Liverpool is entirely occupied by the new red- 

 sandstone formation. The surface of the sand-banks has 

 been estimated to exceed 100 square miles ; on the west and 

 north shores of the bay there are distinct remains of sub- 

 marine forests, stretching beyond low water-mark, which 

 renders it probable that, in former times, these banks existed 

 as a low tract of dry land, now, like the Downs on the south- 

 east coast, encroached on by the sea. 



On approaching the Mersey from the seaward, about fifteen 

 miles from the port, the green colour of the Irish sea is ob- 

 served to change to a brown hue, which increases as the port 

 is neared, until at last the water becomes very opaque, and, 

 when examined in a phial against the light, is found to hold 

 suspended innumerable particles of fine sand. The quantity 

 of sand so mixed with the water, varies with the state of the 

 tide, being least at high-water, and greatest when the ebb 

 and flood are running powerfully, with very shallow water 

 on the banks. That these suspended particles must exercise 



* Read to the; Wernerian Society on Saturday, 7th March 1846. 



