Found in Dungeon Siege II.
Most of the writing in the book is illegible, but you are able to discover that this was the diary of Durin, and Elven historian from Aman'lu. You find one passage particularly interesting.
'... these accursed caves will be the end of me. Why did my ancestors feel compelled to create artifacts of interest as the bottom of every stinking hold on this island?
The Clockwork Bridge in the cave just north of Eirulan, for example -- I can see that there is a lever on the far side of the bridge that I suspect will activate it, but as I have found no way to reach it, full knowledge of this structure may forever be lost to history...'