 | New Jersey Geological Survey, 1835-1840, Henry Darwin Rogers - 1840 - 882 pagina’s
...can be completed in two weeks, and the final report thereon prepared as soon as the mnp is finished. In my last annual report, upwards of eighty iron mines...magnetic iron ores. II. Metallurgy of the iron ores. I. —GEOLOGICAL OCCURRENCE AND PROPERTIES OP THE IRON ORL'S. The different forms in which magnetic... | |
 | Geological Survey of New Jersey, New Jersey Geological Survey - 1857 - 90 pagina’s
...excavated to a very limited extent, many of them containing immense bodies of ore above water-level whick may be economically extracted without the employment...magnetic iron ores. II. Metallurgy of the iron ores. . t.— GEOLOGICAL OCCURRENCE AND PROPERTIES OF THE IRON ORES. The different forms in which magnetic... | |
 | J. Peter Lesley - 1859 - 836 pagina’s
...manufactured into iron in this country, yet they have been excavated to a very limited extent, many of then containing immense bodies of ore above water-level...present annual consumption of iron in the United States. The different forms in which magnetic iron ore occurs in this district, are as follows : First, in... | |
 | John O. Raum - 1877 - 512 pagina’s
...without the employment of expensive machinery. These mines could be made to yield, advantageously, a million tons of ore annually for many years to come, which would be sufficient to supply nearly half of the consumption in the United States. They are situated principally in the counties... | |
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Warren, and within an area of three hundred and sixty square miles. Although some of them have been worked for a century and a half, and in early days furnished a very large proportion of the ore manufactured into iron in this country, yet they have been... 