Subject ASC0003t2h
The geological magazine, or, Monthly journal of geology.
Decade 3:v.1 (1884), Page 158 (1884)
Harvard University, Museum of Comparative Zoology, Ernst Mayr Library
BHL Page 32520051
Keywords
figure 2 circular triangular degrees angles diagram angular rectangle numbers trignometry graphical methods in geology Alfred Harker Graphical Methods Field-Geology field-geology shapes geometry math