INDICATING DRILLING OPERATIONS 
173 
of development on wall maps, pins with heads of various colors 
show in a striking manner the trends of production. It is clear, 
however, that for a set of utility symbols a multi-color system 
cannot be used successfully, because the cost is in many cases 
prohibitive, and because in the common reproduction by blue- 
printing or photography, only black and white symbols may be 
utilized. 
Location. 
O Inadequate. Test. 
0 
Dry Hole. 
0 
Show of OH. 
0 
Oil Well. 
9 The Same- Abandoned. 
0 
Show of Gas. 
Gas. IVe/l. 
~^^The Same -Abandoned. 
Oil Well with ShowofQds 
The Same - Abandoned. 
Oil and Gas Well. 
-^The Same - Abandoned. 
Gas Well with Show of Oil. 
The Same -Abandoned. 
Fig. 3 
THE SUGGESTED SYMBOLS 
In figure 3 is suggested a set of symbols thought to fulfil ade- 
quately the requirements as outlined above. There is no rad- 
ical departure from the present practice, for most, if not all, of 
symbols are in common use. In one instance, the symbol for 
a gas well, it has been necessary to alter a generally accepted 
design. However, inasmuch as the essentials of the design are 
the same and certain complications are avoided, the change should 
