PROCEEDINGS OF THE ACADEMY AND AFFILIATED 



SOCIETIES 



PHILOSOPHICAL SOCIETY OF WASHINGTON 



8 1 8th meeting 



The 8 1 8th meeting was held at the Cosmos Club, April 12, 1919, 

 President Humphreys in the chair; 58 persons present. The minutes 

 of the 817th meeting were read in abstract and approved. 



The first paper was presented by Mr. Wm. Bowie on Mapping the 

 United States for military and civil needs. This paper was illustrated 

 by lantern slides. 



The speaker covered the general phases of map making in the United 

 States and showed the steps that were taken in making the surveys 

 and the resulting map, in any area in which no control or maps existed. 

 No details were given in regard to the technical questions involved, 

 although there are many of great interest in connection with the work 

 in the field, in the drafting room, and in the map reproduction plant. 



There are many uses to which maps can be put and, in general, there 

 is a map for each of the special uses. Some of the maps are very de- 

 tailed in character, showing the natural as well as the cultural features 

 and giving accurate contours to show the elevations and configura- 

 tion of the ground. 



It was said by the speaker that about 40 per cent of the United States 

 has been topographically surveyed but that some of this area will 

 have to be resurveyed on account of the improvement in methods 

 and the more exacting demands of map users. 



The question before the mapping bureaus to-day is the task involved 

 in making accurate contoured maps over the remaining 60 per cent of 

 the area of the country. Before this can be done efficiently, precise 

 leveling and primary triangulation must be carried into much of the 

 unmapped area. The early>completion of the map of the United States 

 would be of great military and civil benefit, as accurate maps are es- 

 sential from a military standpoint in the defense of the country, and 

 from a civil standpoint it is necessary to have them for the efficient 

 development of industries and commerce. 



The speaker said that very accurate maps of large scale should be 

 made along the coasts of the United States for purposes of defense 

 in case of invasion. The war has proved that troops cannot operate 

 effectively without very accurate maps on which a great amount 

 of military detail connected with the movement of troops may be 

 shown. For artillery purposes the maps must be exceedingly accurate, 

 in order that long range firing may be effective. 



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