NORTHERN SCOTLAND. 



343 



If we include mere rocks, the islands dependent upon Scotland must be 

 numbered by thousands ; but official statistics only mention 788 islands, of 

 which 186 were inhabited in 1871, or 4 less than ten years before. The 

 archipelago, properly to be described by such a name, which lies nearest to 

 the Scotch coast, is that formed by the Orkneys, or "Seal Islands," as their 

 Icelandic name has been rendered.* The distance between Duncansby Head 

 and South Ronaldsha, the southernmost of the group, hardly exceeds 6 miles. 

 Pentland Firth, as the separating channel is called, is dreaded for its currents 

 produced by conflicting tides. Off Stroma boils the whirlpool of Swelkie, 



Fig. 168. — Holy Loch, and the rilted-up Loch of Eachaig. 

 Scale 1 : 100,000. 



4° 55' Wo-TG 



1 Mile. 



which a song of the ancient Eddas describes as a mill ever at work to grind the 

 salt of the ocean. During spring tides the current rushes along here with a 

 velocity of ten knots an hour ; and in a tempest which raged in December, 

 1862, the waves, dashing against Stroma, threw up stones and fragments of broken 

 vessels to a height of 200 feet. The strait was no longer wide enough for the passage 

 of the Atlantic waters, and the sea advanced like a wall. Even in ordinary times the 



* Eichard Burton, " Ultima Thule." Others translate, " Islands of the Point " (Thomas, " Xorth 

 Sea Pilot"). 



