CHKONOLOGY — DOUGLASS AND ANTEVS 



317 



tliiclmesses (pi. 2). In the office the measurements are transferred 

 into graphs to enable comparison (fig. 3). Because it is determined 

 by the summer heat, the relative thickness of a varve is, under other- 



r~ 



fT 



rr 



o 



I T,7/ 









T/// 



Ju/y 27, 1923 



Geo/o^ica/ Survey, Canac/a 



Figure 3. — Sample of measurement made in the field and curve constructed from it 



in the office 



