20 MAPS AND THEIR MAKERS 



lines intersecting each other at right angles. This neglect of 

 the convergence of the meridians he considered justifiable in 

 view of the relatively small area of the earth's surface which 

 could be mapped and the uncertainty of much of the data. 

 On this point he was criticized by Ptolemy, who devised two 

 projections and also amended and supplemented Marinus' 

 work from later information. 



In discussing Ptolemy's maps it must be remembered that 

 no manuscript older than the twelfth century a.d. has come 

 down to us, and that it is debatable whether we have the 

 maps as Ptolemy drew them or indeed whether he actually 

 drew maps at all. Apart from general sections on cartography, 

 projections, and Marinus' ideas, the 'Geography' is essentially 

 an extensive table of the geographical co-ordinates of some 

 8,000 localities. Since there were very few actual astronomical 

 observations available, he obtained the positions of these 

 localities by a careful study of itineraries, sailing directions, 

 and topographical descriptions of various countries. In this he 

 endeavoured to allow for the windings of routes, by reducing 

 many of the itinerary distances, for he shared that distrust of 

 travellers' estimates which Marinus displayed when he wrote 

 that ''merchants, being wholty intent on business, care little 

 for exploration, and often through boasting exaggerate dis- 

 tances". The simplest method of arriving at the co-ordinates 

 would be to construct maps from such data, and then to read 

 them off from the network of meridians and parallels. It is also 

 hard to believe that having undertaken all this laborious 

 preliminary work he would have refrained from supplementing 

 his text with maps. This is not to say that we have the maps as 

 they left his hands. Of the world map it is definitely stated that 

 this was drawn by one Agathodaimon of Alexandria, who may 

 have been contemporary with Ptolemy. 



There are also inconsistencies in the text, and between 

 text and maps. Father Joseph Fischer, the great student of the 

 'Geography', considered that the maps were originally drawn 

 by Ptolemy, but that they became separated from the text, and 

 that both underwent modifications before they were brought 

 together again. A recent student, Leo Bagrow, however, has 

 put forward a more drastic interpretation. From a critical study 



