We have spoken so fully of the purpose and general character of this work, in noticing the first volume, that it is hardly necessary for us to speak at length of the second. In a rapid glance at its contents, it appears fully to bear out the promise of the first. We have noticed a few omissions, and some mistakes of judgment. It is, perhaps, impossible to preserve the gradation of reputations in such a work; but a zoologist must be puzzled when he sees Von Baer, the great embryologist, who made a classification of animals, founded on their development, which substantially agrees with that of Cuvier, founded on their structure, occupy about one tenth of the space devoted to Peter T. Barnum; however, we suppose, that, as Barnum created new animals, he is a more wonderful personage than Von Baer, who simply classified old ones. These occasional omissions and disturbances of the scale of reputations are, however, more than offset by the new information the editors have been able to incorporate into most of their biographies of the living, and not a few of those of the dead. Many persons who were mere names to the majority of the public are here, for the first time, recognized as men engaged in living lives as well as in writing books. Some of these biographies must have been obtained at the expense of much time and correspondence. Samuel Bayley, the author of "Essays on the Formation of Opinions," is one of these well-known names but unknown men; but in the present volume he has been compelled to come out of his mysterious seclusion, and present to the public those credentials of dates and incidents which prove him to be a positive existence on the planet. The papers on Arboriculture, Architecture, Arctic Discovery, Armor, Army, Asia, Atlantic Ocean, Australia, Balance of Power, Bank, and Barometer, are excellent examples of compact and connected statement of facts and principles. The biographies of Aristotle, Aristophanes, Augustine, Ariosto, and Arnold, and the long article on Athens, are among the most striking and admirable papers in the volume. As the purpose of the work is to supply a Cyclopaedia for popular use, it is inevitable that students of special sciences or subjects should be occasionally disappointed at the comparatively meagre treatment of their respective departments of knowledge. In regard to the articles in the present volume, it may be said that such subjects as Astronomy and the Association of Ideas should have occupied more space, even if the wants of the ordinary reader were alone consulted. But still, when we consider the vast range and variety of topics included in this volume, and the fact that it comprehends a dozen subjects which a dozen octavos devoted to each would not exhaust, we are compelled to award praise to the editors for contriving to compress into so small a space an amount of information so great.