Architecture is more than just buildings. On the literary front, we should be grateful for the delightful new book \"American City: Detroit Architecture 1845-2005,\" a survey of 50 great Detroit buildings published by Wayne State University Press ($60).With photographs by William Zbaren and text by Robert Sharoff, this large-format book is a love letter to the city from its Chicago-based creators, who came for a visit and found themselves enthralled.