236 ON THE SALINITY OF THE SEA WATER. 



particular years is, of course, easily explained by greater 

 evaporation and smaller rainfall. 



I have observed similar facts at Paglesham and West 

 Mersea, but not in Brightlingsea Harbour and the adjoining 

 creeks, or in Harwich Harbour and up the Stour. 



It thus appears that, at all events in the summer of certain 

 years, the water in some of the Essex estuaries is even more 

 salt than the water outside coming in with the high tide. 

 Along the coast of Essex in summer the sea-water is also 

 somewhat more dense than that of the contiguous part of the 

 North Sea. 



The following table show 7 s the mean densities of the water in 

 summer off the coast, and at high and low water in the estuaries, 

 and the differences, plus or minus, of the low water compared 

 with the high, As will be seen, these differences, though not 

 great, are well marked. It will also be observed that, at all 

 events in summer, the water in the estuaries would be very 

 suitable for the purposes of salt-making by evaporation. 



N.B. — All these numbers refer to the excess of density above 

 rain water, reckoned as 1000. Thus, in the case of the first item 

 in the above list, I give 26*37 instead of 1026*37, which shows 

 the effect of the salts more distinctly, independent of the weight 

 of the w r ater. 



