Instruct: Classify a review into positive or negative sentiment.
Query: Photographic time machine for our nation's capital

Mitchell's book is the fifth in the "Then and Now" series that I've bought, and it is every bit as good as the others. If you are not familiar with the concept, old photographs of particular street corners or buildings are contrasted with corresponding current images. The author displays his detailed knowledge of the area as he recounts stories that accompany each set of photos.Due to the consistency of some of the buildings in Washington, D. C., the main difference between pictures of a certain structure from 100+ years ago and today is only that one is black and white while the newer one is in color. But some locations have been dramatically transformed over time.Any student of history and especially people interested in Washington, D. C. should really enjoy this book.