Profiles constructed graphically from topographic maps are time-consuming 
to prepare and do not show details or breaks in slope that have relief 
less than the contour interval. It is also time-consuming to collect the 
field data needed for construction of profiles because numerous altitude 
measurements must be made along any one line of traverse in order to 
show minor breaks in slope. With an exaggerated profile plotter, 
vertically enlarged cross sections of terrain can be drawn rapidly. 
The combined use of field measured stratigraphic sections and 
vertically enlarged profiles drawn from aerial photographs with the 
exaggerated profile plotter has proved to be an efficient and reliable 
method of stratigraphic and structural study in the Black Hills. 
The instrument is essentially a vertical pantograph that applies the 
principle of proportional triangles to a lever and fulcrum system. It 
consists of the following parts (the relation of each part to the whole 
instrument is shown in figure 2): base plate and track bearing; fulcrum 
bar; vertical track bar; sliding-unit assembly with spring loaded pencil; 
tracing arm bar; and pivot point stud (attaches to tracing table). A 
metal track at the base of the plotting board guides the track-bearing 
assembly along the line of profile. As the carriage of the tracing 
table is moved up and down, the sliding-unit assembly moves a proportion- 
ately greater distance. The enlargement ratio varies with the distance 
from the fulcrum to the pivot point. The instrument shown in the 
figures is designed for 132, 1:3, or 1:5 times enlargement; it could be 
modified for other ratios ranging from 1:1.5 to 1:6. The spring loaded 
pencil produces a clear legible line; fine-line ballpoint pens are 
acceptable also. The instrument can be used with any of the double-