CONTRIBUTIONS OF GEOGRAPHY 187 



charged with the task of supplying the armies with large-scale 

 relief models of the whole front was in itself an impressive 

 organization. A visitor whose credentials admitted him to 

 the upper floor of the Invalides found that a portion of the gal- 

 leries had been transformed into a great laboratory where 

 highly skilled men and women were busily engaged in making 

 plaster reliefs with a speed and with a degree of precision never 

 dreamed of by the ordinary maker of geographic models. 

 Speed was essential, for military operations of the highest im- 

 portance might be awaiting the completion of the models in 

 order that every detail of the battle area could be studied on 

 a miniature reproduction of the original surface. Accuracy 

 was no less essential, for the slopes of the land as shown on the 

 models were often used to determine the trajectories of gun- 

 fire, and hence the kind of artillery necessary to reach certain 

 concealed areas behind hills or mountains; and also to deter- 

 mine quickly and accurately what areas of enemy territory were 

 invisible from any observation post within the Allied lines, and 

 where accordingly the Germans most probably would have 

 depots of importance. The skill developed by the staff of 

 women trained to superimpose on the completed model a tissue 

 paper map of the same scale showing every detail of military 

 value, and to stretch and warp this paper till it adhered to the 

 hills and valleys of the plaster relief without displacing stream 

 lines from the valley bottoms or hill crests from the high points 

 of the model, was most amazing. So perfect was the machin- 

 ery of this organization and so skilled were its employees, 

 that if an army commander telegraphed one morning that he 

 required a relief model of part of his battle front based on 

 a map covering, let us say, 30 to 40 square miles on a scale of 

 3 inches to the mile, the completed model could be shipped 

 to him the evening of the next day, and forty or more addi- 

 tional copies by the following evening. If the terrain was un- 

 usually rough an additional day would be required for the first 

 model. Those accustomed to regard the construction of such 

 models as a matter of weeks, will fully appreciate what this 



