anything which had before been attempted in this country. To the good taste and the technical skill of Mr. Julius Bien, of New York, Mr. King is largely indebted for the beauty and accuracy of this atlas; and it may be a matter of general congratulation among American geologists that it was then demonstrated that the cartographic art had been carried to as great perfection here as anywhere else in the world, and that all known refinements of graphic illustration are within their reach.
All the volumes of the "Report of the Fortieth Parallel Survey," except Vol. I., have been more or less thoroughly reviewed in the scientific journals, and it is therefore unnecessary that they should receive further notice here. It is but just, however, to say of the general character of the report of Mr. King, now for the first time collectively exhibited, that it takes high rank in the literature of the subjects which it considers, and is most creditable to the chief under whose direction the work here recorded was executed, and to his assistants, both for the great amount and excellent quality of that work, and from the good taste and care which the volumes and maps display.
Perhaps no other geologist has enjoyed the opportunity of directing the exploration of so wide and interesting a field, has been so independent and untrammeled in his action, and has had such resources at his command as Mr. King; and something of his success should be ascribed to his good fortune. Yet it is true that he has made excellent use of his exceptional opportunities, and the result can not in justice but be regarded as alike honorable to him, to the War Department under whose auspices the survey was made, and to the country.
In the volume just issued Mr. King has discussed the exposures of all the different systems of rocks which form the geological column, beginning with the Archæan and ending with the Quaternary. He then takes up the volcanic rocks, of which there is such an immense display in the western part of his field, and discusses their relations, succession, and classification. His last chapter is devoted to orography, and is a study of the different and very numerous mountain chains and axes of elevation which occupy so much of the region he has studied. In the progress of this review he has not only made great and important additions to what was before known of the distribution and development of the different geological formations throughout the West, but has subjected each group of rocks and each important topographical feature to close and careful study, with the view of evolving from its ascertained structure the details of its history. In these investigations he has touched upon some of the most profound problems that have engaged the attention of geologists and physicists; and while we can not assert, and he will hardly claim, that all the conclusions he has reached will be confirmed by further observation and mathematical analysis—for all human work is imperfect—yet it can not be denied that the facts he has reported and the inductions he has
