 ... western Kentucky, but centering in Hardin County, Illinois, the availability for optical use of the product from this region has heretofore been neglected, and the United States has been dependent upon foreign sources for its material, which came...  Bulletin - Page 711927Full view - About this book
 | Illinois State Geological Survey - Geology - 1922 - 492 pages
...foreign sources for its material, which came largely through the hands of German optical dealers.3 In connection with a recent geological survey of the...sufficient to supply the needs of the United States. This report is published for the purpose of bringing the matter to the attention of the industries... | |
 | Illinois State Geological Survey - Geology - 1922 - 490 pages
...foreign sources for its material, which came largely through the hands of German optical dealers.3 In connection with a recent geological survey of the...sufficient to supply the needs of the United States. This report is published for the purpose of bringing the matter to the attention of the industries... | |
 | Geology - 1922 - 490 pages
...foreign sources for its material, which came largely through the hands of German optical dealers. 3 In connection with a recent geological survey of the...sufficient to supply the needs of the United States. This report is published for the purpose of bringing the matter to the attention of the industries... | |
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