54 IMPROVED FISHERY HARBOUR ACCOMMODATION 



exposed situations mud cannot repose near the siirface. No 

 one, surely, would expect to find a muddy shore con- 

 fronting an open sea, where the deep water approached 

 closely to the shore, though he would not express surprise 

 at finding such a beach (or foreshore) on the borders of a 

 land-locked bay or of a sheltered estuary. Although the 

 absence of mud in any locality proves nothing, because 

 the tide -currents may sweep it away, or the geological for- 

 mation may not produce it, yet its presence seems both a 

 delicate and certain test of the limits of the utmost possible 

 extent downwards, to which the disturbance originating at 

 the surface has reached. Within 25 miles of Whalsey, in 

 Zetland, we find it in from 80 to 90 fathoms. In the 

 latitude of Wick it occurs in from 60 to 70 fathoms 

 below low water ; in the latitude of Kinnaird Head, 

 on the Norwegian side, in 40 to 50 fathoms ; in the 

 Moray Firth, abreast of Banffshire, we find it in depths 

 of about 35 fathoms ; while as we proceed towards the 

 more sheltered parts of that Firth, we find it rise within 

 20 fathoms of low water, and within the Dornoch Firth 

 we find it within 16; and close in, under the shelter of 

 the Sutherland shore, we find it in only 8 fathoms under 

 the low- water surface. In the latitude of the Firth of 

 Forth we find it in depths of from 30 to 40 fathoms ; and 

 proceeding up the Firth of Forth, we find it gradually 

 rising nearer the low-water level, in proportion as the 

 shelter increases, from 22 fathoms at Dunbar up to 3 

 fathoms off Leith ; while beyond Queensferry we find the 

 mud actually rising above low water, even although the 

 current gets stronger, as we ascend the estuary." 



" In the northern bottom of the Firth of Forth the mud 

 gradually rises from 22 fathoms near Fife-Ness, up to 8 

 fathoms near Burnt Island ; whereas near Leith it exists in 



