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Rh for each of the digital numbers. The pictures of the first series are designed for language-lessons, in which the particular number is brought in and visibly represented, and the immediate design of which is to excite thought and cultivate expression. The second series consists of slate exercises involving the numbers to be copied with changes; and these are afterward changed into diagrams, combining exercises in elementary drawing, into which the several numbers also enter. The third series of pictures, entitled "What can you tell?" presents combinations, with the numbers still the most prominent objects to be considered, which the child is invited to describe, or concerning which he may compose a story—exercises which call the imagination into play, and encourage independent and original expression. These lessons are followed by a series of reading lessons in number and dictation exercises, in combinations of from one to ten, with the pictorial element still employed. In the third part are given combinations in numbers from ten to twenty.

book, representing a more advanced stage of the study of geology than is furnished in the author's "Geological Excursions," is intended to introduce the reader to the science by some natural and pleasant method; to help him to see things for himself, and draw his own conclusions from them. It is, therefore, designed to be a guide to the observation of Nature, and a synoptical record of the more important facts and doctrines of the science. It is divided into two parts: "Geology inductively presented," and "Geology treated systematically." Geology is the science which treats of the earth; the earth is under our feet; let us, therefore, the author says, "direct our attention to it, and see what facts may be observed. These will be geological facts. Every fact learned by observing the earth is part of the science; and the things observed near home are just as real science and just as important as those in distant lands, of which we may read in the books." The drift being nearly everywhere, the reader is invited to make that the special subject of his study. He will find in it representations of a great variety of geological phenomena and formations, minerals and fossils. He can make the facts he learns from it the basis of his more extended studies in excursions, or in books, after he has well traversed the field in which he is able to make excursions. The outcome of the first, or inductive, part of the book, in which the course is carried far enough to illustrate how to study fossils in a scientific way, "is a somewhat chaotic and undigested mass of facts and doctrines buried in a considerable volume of verbiage. It does not assuredly supply the means for a methodized apprehension of the elements of the subject, but it supplies many fundamental facts, many great principles, many impressions, many hints for personal observation, and many impulses to continue. Far better for the student to get so much than to leave school in total ignorance of a science which sustains so important relations to industries, to culture, and to civilization. Part II is the complement of this. Here the whole body of facts and principles is reduced to a methodical representation. . . . Here, too, the discussions of the several topics are completed, and the various portions are adjusted to a logical relation." The book treats principally of American geology, and in this all the recent additions, which have transformed the science so that "the subject has to be treated very much as if no elementary book had been written," have been made use of. The motto of the first part is, "How we may observe the facts, and learn their meaning." The successive chapters of the second part, which are divided into many special sections, treat of "lithological," "structural," and "dynamical" geology, the "progress of terrestrial life," and "formational" and "historical" geology.

book was prepared for the use of students in the summer course in botany at Harvard University, in which the author is