A sequence of twelve maps from the mid-nineteenth century reveal that they were accurate enough for planning and executing middle-sized water control projects for the department of Dengchuan in southwest China according to University of Hertfordshire researchers and published in Water History.
Fuente : http://www.alphagalileo.org/ViewItem.aspx?ItemId=1...
Fuente : http://www.alphagalileo.org/ViewItem.aspx?ItemId=1...