"Over twenty years have passed since the First Edition was published in 1998; in that time changes both technological and human have occurred. Regarding human changes, we regret the death of one of the co-authors, Dr. Paul S. Cohen, just as preparations began in 2004 for the Second Edition. Hence this book has a new co-author, Dr. Stephen M. Cohen. The basic premises and criteria for inclusion in our book, however, have not altered. The GPS has rendered the art of map-reading nearly obsolete and many sites have added instructions to their facilities. Thus we have removed the need for us to include detailed directions. In addition the Internet now provides most of us with a ready and quick fountain of site information, sometimes accurate, and occasionally not. This information includes details about most of the sites we have chosen to include in the Second Edition, such as temporary exhibits, changeable daily schedules of lectures, and guided tours. In fact, many websites even provide driving directions. By request of our readers we have included information about how to go to sites by public transportation. In the Second Edition, we continue our focus on providing an ancillary background to each site, including some of the unusual, unique, or important aspects of its collection. As before, at least one of the authors has visited practically every site we discuss. We now include each site's own website and unusual directions such as latitude and longitude to correct for occasional errors in GPS directions or when a site may be reached by water as well as land. Because this book showcases science and technology for a worldwide readership, we now indicate metric units as well as English units for all measurements. This edition now lists treasures in all fifty states. We have split America's Scientific Treasures into three separate volumes, highlighting different geographical areas of the United States: the East Coast, the Midwest, and the West. In this way, you, the user, can more easily carry this book as you travel"--