Ore Deposits

summaries of the history of the various branches of geology and mineralogy in the last hundred years, mainly from the American standpoint, but still with complete acknowledgment of the value of work done in other countries. Of special interest, because somewhat novel, is the chapter entitled " A Century of Government Geological Surveys" by Director George Otis Smith, giving a detailed account of the beginnings and subsequent progress of that vast organization known as the United States Geological Survey, which has accomplished such wonders in the exploration and development of the resources of the country. This book leaves on the mind of the reader a feeling of admiration at the manysidedness, activity, and originality of geology and the allied sciences in America at the present time.