F. E. Nipher—Magnetic Survey of Missouri. dll 
tions of the St. Louis Academy of Science. In the original 
map, the horizontal scale is 20 miles to the inch, the elevations 
being exaggerated 200 times. This exaggeration was neces- 
sary in order to bring out the form in the photograph, since on 
4 relief map 150 feet square, the greatest difference in elevation 
In the State drawn-to the same scale would be Bs eaoaione by 
4 vertical height of one inch. The horizontal scale of the cut 
18 62 miles to the inch. Three stations in the Missouri valley 
