180 ANNUAL REPORT SMITHSONIAN INSTITUTION, 194 5 



the exercise of sound and objective judgment. While acknowledging 

 this outstanding contribution of my colleagues, I must absolve them 

 of any responsibility for the comments herewith as to the national 

 significance of the estimates, as these represent largely my own views. 

 It would be easy to avoid the responsibility of estimating national 

 mineral reserves on the grounds that there are so many unpredictable 

 and unforeseen factors involved in the occurrence and discovery of 

 mineral deposits that it is futile to be specific on a quantitative basis. 

 However, despite the limitations in estimates of this kind, I believe 

 it is helpful to have well-informed men make available their opinions 

 on the magnitude of our reserves as such information provides a 

 practical basis for discussion. Moreover, many basic decisions on 

 national policy will have to be made by our leaders within the next 

 few years, and those decisions can be made more wisely if the objective 

 judgment of experts is available. The data to be presented this 

 evening represent only the highlights of the reports prepared by these 

 men. They should be used with the understanding that reserve 

 estimates are subject to change even under the best of conditions, 

 particularly when attempted on such a broad scale. The estimates 

 therefore represent preliminary figures only. 



BASIS OF RESERVE ESTIMATES 



111 attempting this appraisal of our mineral position major emphasis 

 has been placed on those reserves that are available under present 

 economic conditions and technologic practices. They may be referred 

 to broadly as "commercial" reserves. Future supply-demand relation- 

 ships and prices as well as progress in mineral technology are not sus- 

 ceptible to precise determinations. Consequently the economic and 

 technical factors involved in estimates of commercial reserves, in addi- 

 tion to the geological factors, must be analyzed in broad terms. The 

 data available do not permit detailed estimates within various narrow 

 price ranges. In general, the estimates may be considered as repre- 

 senting reserves available at good prewar prices, although some of 

 them are predicated on moderately higher prices. 



Company reports and other public statements on mineral reserves 

 frequently include only such quantities as are practically assured on 

 the basis of engineering data. They, therefore, present an extremely 

 conservative appraisal of potential mineral supplies and are apt to be 

 misleading if they are not used in proper perspective. To present a 

 more realistic picture of our mineral potential, the Survey-Bureau 

 specialists have for most commodities evaluated commercial reserves 

 on the basis of measured, indicated, and inferred ore, using the official 

 definitions that have been established for these categories. Notable 



