A set of approximately 1,800 historical maps of South Asia produced by the Survey of India at a scale of 4 miles per inch (1:253,440) or the modern metric equivalent of 1:250,000. These maps cover the territory from Eastern Persia (Iran) through present day Afghanistan, Pakistan and India and on to Burma, and parts of Western China and Southeast Asia, and were produced during the late 19th and much of the 20th century. The file naming convention is to first give the number of the 4 degree x 4 degree block followed by the letter (A to P) of the sixteen 1 degree x 1 degree blocks in each 4 degree block eg. 38 D. This is followed by the name of a town or geographical area encompassed by the map, followed by the date of publication in paren...