MATHEMATICAL GEOGRAPHY, $1.00
By WILLIS E. JOHNSON, Ph. D., Vice-President and Professor of Geography and Social Sciences, Northern Normal and Industrial School, Aberdeen, South Dakota.
This work explains with great clearness and thoroughness that portion of the subject which not only is most difficult to understand, but also underlies and gives meaning to all geographical knowledge. A vast number of facts which are much inquired about, but little known, are taken up and explained. Simple formulas are given so that a student unacquainted with geometry or trigonometry may calculate the heights and distances of objects, the latitude and longitude of a place, the amount any body is lightened by the centrifugal force due to rotation, the deviation of a plumb-line from a true vertical, etc.
AMERICAN BOOK COMPANY
ELEMENTS OF GEOLOGY
By ELIOT BLACKWELDER, Associate Professor of Geology, University of Wisconsin, and HARLAN H. BARROWS, Associate Professor of General Geology and Geography, University of Chicago.
$1.40
An introductory course in geology, complete enough for college classes, yet simple enough for high school pupils. The text is explanatory, seldom merely descriptive, and the student gains a knowledge not only of the salient facts in the history of the earth, but also of the methods by which those facts have been determined. The style is simple and direct. Few technical terms are used. The book is exceedingly teachable.