NATIONAL SURVEYS AND MODERN ATLASES 165 



introducing a measure of uniformity in international carto- 

 graphy. The value of the 1/1 M. sheets for the mapping of 

 distributions on a continental or world-wide scale has also 

 been recognized. The sheets have been used for example 

 for the International Map of the Roman Empire, of which 

 twelve sheets have been published. The recently inaugurated 

 World Land Use Survey aims at eventually producing maps on 

 this scale. The value of the latter map in plans for assisting 

 the under- developed areas would be considerable. 



But perhaps the most striking result of the International 

 Million Map was the impetus it gave to the Million Map of 

 Hispanic America which was produced by the American 

 Geographical Society on the initiative of its former Director, 

 the late Isaiah Bowman. The map follows the specifications of 

 the International Map quite closely, and in its compilation the 

 Society has had the approval and assistance of South American 

 governments. Begun in 1920, it was completed with the publica- 

 tion of the 107th sheet in 1945. The complete map covers an 

 area whose greatest dimensions are 34 X 28 feet; a staff of seven 

 were employed throughout the twenty-five years in research, 

 compilation and drawing. Compilation required the assessment 

 of the relative values of a great quantity of surv^ey material, 

 and research brought to light much useful data preserved in 

 government and commercial offices. Where survey data were 

 entirely lacking, written descriptions were used to discover 

 physiographic characteristics. To indicate the accuracy of the 

 material employed, a reliability diagram was included in each 

 sheet, a useful practice since followed by other cartographic 

 institutes. 



The Development of the Atlas 



The representation on maps of features other than those 

 strictly topographical in character was of course not new. 

 The printed versions of Ptolemy's maps were in reality historical 

 maps, and most of the great cartographers of the sixteenth and 

 seventeenth centuries had published maps to illustrate Biblical 

 history. In the domain of science Edmund Halley had mapped 

 the tides of the English Channel, and the lines of equal 



