142 LL OSAL RMB ATIN: 
able and serviceable. In the present oil development at Boulder, 
Colo., the Hayden map has been of the highest service. No 
doubt a more detailed map would be much better, but upon the 
Hayden base each oil expert can make a map of his own. If the 
investor were to wait until a proper map could be made by gov- 
ernment or state officials, he would find the best territory all 
pre-empted and drilled. 
So far, then, as helping in the development of new mining 
districts is concerned, it should be the first duty of the geologist 
to furnish good reconnoissance maps giving general data regard- 
ing (1) lithology, (2) structure, and (3) age. In spite of the 
limitations and inaccuracies of such maps their tremendous use- 
fulness is sufficient warrant for their production. 
I would not be understood as decrying the making of 
detailed maps. By no means. Let us have as many of such 
maps and as much detail as possible; but let us have first the 
reconnoissance maps and later, after the prospector and miner 
have developed a few good properties and opened up the 
ground enough to enable the geologist to get a right under- 
standing of the structure and the ore bodies, let as detailed a 
map as possible be made. Such a map will be of the highest 
service in the development of a general plan of operation; the 
laying out of long cross-cut tunnels or the locating of deep 
shafts. Studies of the genesis of the ores made at the same 
time will indicate the probability as to the permanence of the ore 
bodies and give a reliable answer to the question of the erection 
of large permanent works, the building of railways, smelters. 
etc. In the beginning of mining operations these questions do 
not need to be answered. It is fortunately true that the initial 
operations are nearly always small and individual. It takes time 
to interest capital, to reconcile conflicting interests, and to bring 
about the economic conditions necessary to operations on a 
large scale. During the interval the general map is sufficient. 
There are no large works to be planned and it would be impos- 
sible to carry them out if there were. When, however, the 
