On Monday, September 30, 2013 8:34:18 AM UTC-5, Ivan Vegvary wrote:
Daughter wants to put 3 to 4 'peninsulas' into the attic/apartment to break up the 50 foot length.

This simple, small bookcase was used in college, almost 40 yrs ago, and is now used in my upholstery shop. It's nailed together and stable. You could improve on it, make it prettier, max stablillity with better jointery, make it a little larger (this one's 27"L X 22.5"H X 9.5"W. It's simple decor, can be moved, butted with another. I've made several of these (improved design & jointery) for several family member's children. Or maybe use aspects of its design for whatever bookcase you build. 3 pics: http://www.flickr.com/photos/43836144@N04/10024949314/

Does your bookcase need to be attached to the wall or floor? For the heigth you're suggesting, I would think a free standing case would do fine.

Sonny