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.