Abstract: | At the beginning of the twentieth century, little of the world outside of Europe, India, and parts of North America had been covered by topographic mapping. By the end of the century there were few areas that were not covered by topographic mapping, if only at small scales. Most of the technological changes that made this extension of map coverage possible were pioneered dunng the period 1900-1939. This paper reviews the technological deveiopments in land and air survey that took place during that period and relates them to the drive to produce cost-effective mapping for civil and military purposes. |