PART ONE INTRODUCTION I Change of Position II Spontaneous Measurement PART TWO CONSERVATION AND MEASUREMENT OF LENGTH III Reconstructing Relations of Distance IV Change of Position and the Conservation of Length V The Conservation and Measurement of Length VI Subdividing a Straight Line PART THREE RECTANGULAR COORDINATES, ANGLES AND CURVES VII Locating a Point in Two or Three Dimensional Space VIII Angular Measurement IX Two Problems of Geometrical Loci: the Straight Line and the Circle X Representation of Circles, Mechanical and Composite Curves PART FOUR AREAS AND SOLIDSXI The Conservation and Measurement of an Area and Subtracting Smaller Congruent Areas from Larger Congruent XII Subdivision of Areas and the Concept of Fractions XIII Doubling an Area or a Volume XIV The Conservation and Measurement of Volume PART FIVE CONCLUSIONS XV The Construction of Euclidean Space: Three Levels