Various 
Oppressions of the Sixteenth Century in the Islands of Orkney and Zetland: From Original Documents [PDF ebook] 

The History of Orkney and Zetland is still to be written. There is no part of the United Kingdom which possesses historical materials more ample, or more early, and none so little known as these, the last acquired of the British Isles. But where the sources of information are so scattered and inaccessible, it is perhaps easier to estimate the amount of attainable knowledge, than to fathom or fill up the depths of inevitable ignorance, and I am far from pretending to supply this desideratum. I still hope to see it in abler hands, when the same research, learning and acumen, which have done so much to elucidate the Celtic history of the North of Scotland, shall be applied to the parallel subject of these not less interesting Islands. In my essay on a theme so difficult both from its antiquity and its novelty, I shall account it a sort of success, if my statements, omissions or mistakes, shall tempt or provoke some more capable or more practised inquirer—more earnest, and more honest in the search for truth, he cannot be.