The historical atlas of South Asia may go down in history as one of the great academic achievements of the 20th century. Sadly, the 15-pound, $250 tome has gone out of print. But, happily, it is now available for free online at the Universitiy of Chicago's Digital South Asian Library at [].

An effort started in 1964, the Atlas was based on the foundation of the Ames Library of South Asia, a collection that began in 1917 when Charles Lesley Ames and his bride went to India. When he gifted his treasury of text to the University of Minnesota in 1961, it comprised 80,000 items, including more than 25,000 volumes and 700 maps. In 1966 Professor Joseph E. Schwartzberg took the post of editor and was joined by part-time contributors Eleanor Zelliot and cartographer Raj B. Mathur. Historian Shiva G. Bajpai joined full time in 1967. Many others contributed over time to the 1978 first edition. By the time the second edition was published in 1992, a staggering 190 man-years of work had been invested in the masterpiece.

The first 159 pages of the book contain fascinating maps detailing the physical geography, social and cultural landscapes from prehistory to the Vedic period, through independence and up to 1961. You can see exactly where Neolithic and Harappan tools were found, follow the movements of kingdoms, cultures, religions and saints across the ages, chart the spread of Indian culture all the way to Vietnam and follow India's modern-day political divisions and urbanization.

Pages 151 to 375 provide a fascinating historical text. Journey back to the 4th century and learn about the rise of the Hindu Gupta dynasty on the Gangetic plain, then come forward to just before Independence and learn about details of India's first elections. Far more than a book of maps, as the name implies, this atlas is an awesome and accessible encyclopedia of Indian history.