Frontmatter -- INTRODUCTION TO VOLUME 3 -- CONTENTS -- 1 [ELEMENTS OF TRIGONOMETRY] -- 2 MULTITUDE AND QUANTITY -- 3 PROBABILITY -- 4 FINITE DIFFERENCES -- 5 BOOLIAN STUDIES -- 6 LOWELL LECTURES, 1903 -- 7 EXISTENTIAL GRAPHS -- 8 THE FOUR-COLOR PROBLEM -- 9 MAP PROJECTION -- 10 LINEAR ALGEBRA AND MATRICES -- 11 POLITICAL ECONOMY -- 12 AMAZING MAZES -- 13 LOGIC MACHINES -- 14 MEASUREMENT -- 15 NON-EUCLIDEAN GEOMETRY -- 16 APPLICATION OF MATHEMATICS -- 17 N-VALUED LOGIC